Fast, local, privacy-first utilities
Every tool runs entirely in your browser — no accounts, no telemetry, no network calls, and nothing you paste is ever uploaded. Data is processed on-device and forgotten when you close the tab.
Cron Expression Parser & Builder
Turn a cron expression into plain English and its next five run times — or build one field by field.
Open tool → tools/dev/hash-hmac-studio/Hash & HMAC Studio
Compute MD5, SHA-1, SHA-256 and SHA-512 digests from text or files, with optional keyed HMAC mode. Nothing leaves the page.
Open tool → tools/dev/jwt-decoder/JWT Decoder & Expiration Visualizer
Decode a compact JWT into its header and payload, inspect claims and validity, and visualize expiration.
Open tool → tools/dev/api-inspector/API Payload Inspector
Paste any API request or response — auto-detects JSON, JWTs, Base64 and timestamps, generates TypeScript types, and redacts secrets on-device.
Open tool → tools/dev/regex-sandbox/Regex Sandbox
Compose a regular expression, watch it match against your test string live, and inspect every capture group.
Open tool → tools/dev/uuid-generator/UUID / ULID Bulk Generator
Bulk-generate UUID and ULID identifiers with adjustable counts and copy-ready output.
Open tool → tools/dev/ssh-keypair-generator/SSH Keypair Generator
Generate Ed25519 or RSA keypairs in-browser via Web Crypto, with fingerprints and copy-ready output.
Open tool → tools/dev/cors-header-tester/CORS Header Tester & Generator
Inspect a URL's CORS posture and generate correct Access-Control headers for your own endpoints.
Open tool → tools/dev/wcag-contrast-studio/WCAG Contrast & Palette Studio
Check color pairs against WCAG AA/AAA ratios and build accessible palettes with live previews.
Open tool → tools/dev/vector-qr-studio/Vector QR Code Studio
Create crisp QR codes as pure SVG with adjustable error correction, colors and quiet zone.
Open tool → tools/dev/env-leak-checker/.env Leak Checker
Paste a .env file or config dump and surface secrets that should never reach a repository.
Open tool → tools/dev/chmod-calculator/Chmod Permissions Calculator
Compute octal and symbolic file permissions from owner/group/public checkboxes and back again.
Open tool → tools/dev/sql-beautifier/SQL Beautifier & Query Optimizer
Format minified SQL into readable queries with keyword casing and indentation control.
Open tool → tools/dev/subnet-cidr-calculator/Subnet/CIDR Calculator
Break down IPv4 CIDR blocks into network, broadcast, mask, host range and usable counts.
Open tool → tools/dev/entity-escaper/HTML/SQL Entity Escaper
Escape and unescape HTML entities and SQL string literals safely for embedding or logging.
Open tool → tools/dev/graphql-formatter/GraphQL Schema Formatter
Pretty-print GraphQL schemas and operations with sorted fields and consistent indentation.
Open tool → tools/dev/user-agent-parser/User-Agent String Parser
Decode any User-Agent string into browser, engine, OS and device with confidence notes.
Open tool → tools/dev/minifier-studio/Minifier Studio (JS/CSS/HTML)
Minify JavaScript, CSS and HTML locally with size-savings stats before you ship.
Open tool → tools/dev/dedup-lines/Duplicate Line Deduplicator
Remove duplicate lines while preserving order, with optional case-insensitive matching.
Open tool → tools/dev/lorem-ipsum-generator/Lorem Ipsum & Fake JSON Generator
Generate lorem paragraphs or fake JSON payloads at any size for testing and mocking.
Open tool → tools/dev/css-gradient-studio/CSS Gradient Studio
Design linear and radial gradients visually and export clean, minimal CSS.
Open tool → tools/dev/markdown-editor/Markdown Live Editor & PDF Exporter
Write Markdown with live preview and export to styled HTML or print-ready PDF.
Open tool → tools/dev/markdown-preview/Markdown Preview
Live GitHub-flavored Markdown preview with copyable HTML output.
Open tool → tools/dev/pdf-watermark/PDF Page Numbering & Watermark
Add page numbers, headers or watermark text to PDF documents entirely in your browser.
Open tool → tools/dev/hash-generator/Bcrypt/Argon2 Hash Generator & Verifier
Generate and verify bcrypt and Argon2 password hashes locally with configurable cost factors.
Open tool → tools/dev/tls-cert-decoder/TLS/SSL Certificate Decoder
Paste a PEM certificate to decode subject, issuer, SANs, validity and expiry timeline.
Open tool → tools/dev/ssh-fingerprint/SSH Key Fingerprint Inspector
Inspect SSH public keys and compare fingerprints across MD5 and SHA-256 formats.
Open tool → tools/dev/json-patch-generator/JSON Patch/Diff Generator (RFC 6902)
Diff two JSON documents and emit RFC 6902 patch operations ready to apply.
Open tool → tools/dev/sqlite-viewer/SQLite DB Viewer & Query Runner
Open a SQLite database file in your browser, browse tables and run read-only queries.
Open tool → tools/dev/duckdb-analyzer/DuckDB-WASM Analytical Query Tool
Run analytical SQL over CSV, JSON and Parquet in-browser via DuckDB-WASM — no server needed.
Open tool → tools/dev/code-diff-viewer/Monaco Code Diff Viewer
Compare two code snippets side by side with Monaco-powered syntax highlighting.
Open tool → tools/dev/data-pipeline/Multi-Operation Data Pipeline
Chain trim, filter, map, split, join and regex steps over text or JSON datasets.
Open tool → tools/dev/raw-image-viewer/RAW Camera Image Viewer
Preview camera RAW files with histograms and extract embedded JPEG previews locally.
Open tool → tools/dev/p2p-file-transfer/WebRTC P2P File Transfer
Send files directly between devices over WebRTC with no uploads, servers or accounts.
Open tool → tools/dev/lottie-editor/Lottie Animation Editor
Inspect, tweak and recolor Lottie animations frame by frame without After Effects.
Open tool → tools/dev/terraform-diagram/Terraform HCL Diagram Renderer
Render Terraform HCL into an infrastructure diagram of resources and their dependencies.
Open tool → tools/dev/k8s-resource-sizer/Kubernetes Resource-Limit Sizer
Size Kubernetes CPU and memory requests/limits from workload profiles and replica counts.
Open tool → tools/dev/repomix-bundler/Repomix Web Bundler
Pack a set of source files into one LLM-ready context bundle with a tree overview.
Open tool → tools/dev/mermaid-diagram-studio/Mermaid.js Diagram Studio
Author Mermaid diagrams with live local rendering and SVG/PNG export — no CDN calls.
Open tool → tools/dev/json-erd-generator/JSON Visual ERD Generator
Turn JSON samples into visual entity-relationship diagrams automatically.
Open tool → tools/dev/embedding-size-estimator/Vector Embedding Dimension Size Estimator
Estimate vector index memory and storage needs for embedding models before you deploy.
Open tool → tools/dev/yaml-json-toml-converter/YAML ↔ JSON ↔ TOML Converter
Convert configuration between YAML, JSON and TOML with precise syntax-error reporting.
Open tool → tools/dev/bitwise-base-n-calculator/Bitwise & Base-N Calculator
Convert hex, dec, oct and bin values and apply AND/OR/XOR/NOT plus shifts at any bit width.
Open tool → tools/dev/timestamp-converter/Timestamp Converter
Convert Unix epochs to ISO-8601 and human-readable time in any timezone, with batch mode.
Open tool → tools/dev/base64-encoder/Base64 Encoder / Decoder
Encode and decode Base64 text, switch to URL-safe alphabets, or turn files into data URIs.
Open tool → tools/dev/url-parser-builder/URL Parser & Builder
Break a URL into scheme, host, path and query, edit components, and rebuild clean links.
Open tool → tools/dev/color-converter/Color Converter
Convert hex, RGB and HSL in both directions with an instant tints-and-shades generator.
Open tool → tools/dev/text-case-converter/Text Case Converter
Switch text between camelCase, snake_case, kebab-case, CONSTANT_CASE, Title Case and URL slugs.
Open tool → tools/dev/css-grid-flexbox-generator/CSS Grid & Flexbox Layout Generator
Visual grid and flexbox layout builder with live preview, gap controls and exportable CSS.
Open tool → tools/dev/og-twitter-preview/Open Graph & Twitter Card Meta Previewer
Paste a URL or meta tags to preview how your page will look when shared on social platforms.
Open tool → tools/dev/whisper-cost-estimator/Whisper Audio Transcript Cost Estimator
Estimate OpenAI Whisper API costs from audio file size, format and language settings.
Open tool → tools/dev/json-schema-generator/JSON to Type Schema Generator
Generate TypeScript or JSON type schemas from a JSON sample with optional and strict options.
Open tool → tools/dev/har-waterfall-reader/HAR Waterfall Reader
Parse a HAR export and visualize request timings as a waterfall with per-phase breakdowns.
Open tool → tools/dev/webhook-tester/Webhook Tester / Replayer
Send and replay HTTP webhook payloads to any endpoint with custom method, headers and body.
Open tool → tools/dev/openapi-validator/OpenAPI / Swagger Validator & Mock Generator
Validate an OpenAPI/Swagger spec and generate mock responses from its schema in the browser.
Open tool → tools/dev/graphql-cost-estimator/GraphQL Query Cost Estimator
Estimate server cost of a GraphQL query by analyzing resolved fields, depth and complexity.
Open tool → tools/dev/api-waterfall-visualizer/API Response Waterfall Visualizer
Visualize a series of API responses as a waterfall of timing and size bars at a glance.
Open tool → tools/dev/grpc-protobuf-decoder/gRPC / Protobuf Message Decoder
Decode gRPC/Protobuf messages from base64 or hex input into readable field/value trees.
Open tool → tools/dev/markdown-mindmap-renderer/Markdown Outline / Mindmap Renderer
Render a Markdown outline as an interactive mindmap diagram entirely in the browser.
Open tool → tools/dev/markdown-slide-deck/Markdown Slide Deck Presenter
Turn Markdown into a full-screen slide deck with keyboard navigation and progress.
Open tool → tools/dev/llm-token-cost-estimator/LLM Token Counter & API Cost Estimator
Count tokens in pasted text with common estimation methods and estimate LLM API cost per model family (GPT, Claude, Llama).
Open tool → tools/dev/ai-prompt-builder/AI System Prompt Builder & Variable Injector
Assemble AI system prompts from reusable blocks, inject variable placeholders with defaults, and validate coverage live.
Open tool → tools/dev/prompt-builder-studio/Prompt Builder Studio — Midjourney / SD / Flux
Build structured creative prompts for Midjourney, Stable Diffusion and Flux with subject, style and parameter modules.
Open tool → tools/dev/screenshot-beautifier/Screenshot Beautifier
Drop a screenshot into a mock device frame and export a clean, captioned share version.
Open tool →RV Park Utility Cost Recovery Analyzer
Model four ways of recovering park electricity costs and compare annual recovery, metering CapEx and payback.
Open tool → tools/dev/curl-converter/Curl-to-Multi-Language Converter
Translate cURL commands into fetch, Python, Go and other languages, ready to paste.
Open tool → tools/finance/cleaning-bid-calculator/Commercial Cleaning Bid & Labor Cost Calculator
Price commercial cleaning jobs from area, frequency and labor assumptions with margin control.
Open tool → tools/media/exif-stripper/EXIF Metadata Stripper
Remove GPS coordinates and identity metadata from images before publishing them.
Open tool → tools/finance/invoice-generator/Invoice Generator
Build printable A4/Letter invoices with line items, tax and discounts — fully offline.
Open tool → tools/finance/tip-split-calculator/Tip & Bill Split Calculator
Split bills any way with tip presets, per-person totals and round-up options.
Open tool → tools/finance/sales-tax-calculator/Sales Tax / VAT Calculator
Add or extract sales tax or VAT with saved rates and reverse calculation.
Open tool → tools/finance/asset-depreciation-calculator/Asset Depreciation Calculator
Straight-line depreciation schedules with salvage value and year-by-year book value.
Open tool → tools/finance/turo-roi-calculator/Turo ROI Calculator
Estimate return on investment for peer-to-peer car rental with maintenance, insurance and utilization.
Open tool → tools/finance/coworking-desk-yield/Coworking Desk Yield & CapEx Modeler
Model desk utilization, revenue yield and capital expenditure payback for coworking spaces.
Open tool → tools/finance/compound-interest/Compound Interest Calculator
Compute compound interest with flexible compounding frequencies and see growth over time.
Open tool → tools/finance/simple-interest/Simple Interest Calculator
Calculate simple interest from principal, rate and time period with instant results.
Open tool → tools/finance/rule-of-72/Rule of 72 Calculator
Estimate how long it takes for an investment to double at a given annual rate of return.
Open tool → tools/finance/pv-fv-calculator/Present Value / Future Value Calculator
Convert between present and future values using discount or growth rates over time.
Open tool → tools/finance/loan-amortization/Loan Amortization Calculator
Generate a full amortization schedule with monthly payment breakdown and total interest.
Open tool → tools/finance/annuity-calculator/Annuity Calculator
Calculate present or future value of an annuity with regular payments and compound interest.
Open tool → tools/finance/cd-apy-calculator/CD / APY Calculator
Compare certificate of deposit yields and see effective APY across different compounding periods.
Open tool → tools/finance/savings-goal/Savings Goal Calculator
Determine how much to save monthly to reach a financial goal by a target date.
Open tool → tools/finance/net-worth-calculator/Net Worth Calculator
Track total assets versus liabilities to calculate and monitor your net worth over time.
Open tool → tools/finance/mhp-water-passthrough/MHP Water Pass-Through Calculator
Model water utility cost pass-through for a mobile home park from lot count and the utility bill, with submeter versus base re-allocation and per-lot monthly charges.
Open tool → tools/finance/saas-ltv-cac/SaaS LTV / CAC Calculator
Compute SaaS unit economics — LTV, CAC, LTV:CAC ratio and payback period — from MRR, churn, gross margin and acquisition cost.
Open tool → tools/finance/llc-filing-fees/LLC Filing Fee Matrix
Compare LLC formation filing fees by state with a side-by-side reference matrix. Neutral reference data, not legal advice.
Open tool → tools/finance/equipment-lease-vs-buy/Equipment Lease vs. Buy Analyzer
Compare leasing versus buying equipment over a term: lease payments versus purchase, financing, depreciation and residual value, with a total-cost-of-ownership comparison.
Open tool → tools/finance/cap-rate-cash-on-cash/Cap Rate / Cash-on-Cash Calculator
Real-estate investment metrics: capitalization rate (NOI / property value) and cash-on-cash return (annual pre-tax cash flow / cash invested).
Open tool → tools/finance/freight-volumetric-weight/Freight Volumetric Weight Calculator
Calculate dimensional weight for freight and shipping, compare billable versus actual weight, and see which the carrier charges.
Open tool → tools/finance/title-insurance-closing/Title Insurance / Closing Cost Calculator
Estimate property closing costs including title insurance, escrow, lender fees, recording, transfer tax and prorations with a line-item breakdown.
Open tool → tools/finance/restaurant-food-cost/Restaurant Food Cost Calculator
Compute food cost percentage, ideal versus actual food cost and menu contribution margin, and set menu prices from a target food cost.
Open tool → tools/finance/hvac-btu-sizing/HVAC BTU Sizing Calculator
Estimate heating and cooling load for a room or home from area, insulation, windows, occupancy and sun exposure, then suggest a capacity.
Open tool → tools/finance/mortgage-refinance-breakeven/Mortgage Refinance Break-Even Calculator
Compare an existing mortgage against a refinance, with new payment, closing costs, monthly savings and months-to-break-even point.
Open tool → tools/finance/freelance-retainer-modeler/Freelance Retainer Overage & Scope Modeler
Model a freelance retainer with included hourly scope, overage billing above it and scope-change tracking to price what a client should be charged.
Open tool → tools/finance/commercial-lease-escalation/Commercial Lease Escalation Calculator
Project commercial rent over a lease term under fixed, percentage and CPI-indexed escalation clauses with a year-by-year schedule.
Open tool → tools/finance/subcontractor-retainage/Subcontractor Retainage & Pay Application Modeler
Model construction retainage and pay applications: contract value, retainage held, prior billings, current draw and cumulative earned versus retained.
Open tool → tools/finance/amazon-fba-dim-weight/Amazon FBA Dimensional Weight Fee Tool
Estimate Amazon FBA fulfillment fees from package size tier, dimensional versus actual weight and estimated fee schedule.
Open tool → tools/finance/stripe-vs-paypal-fees/Stripe vs PayPal Merchant Fee Splitter
Compare payment processor fees: enter flat and percentage fees plus per-transaction fixed costs for two processors and see the per-transaction net, breakeven amount and winner at different ticket sizes.
Open tool → tools/finance/str-cleaning-fee-margin/Short-Term Rental Cleaning Fee Margin Tool
Model your short-term rental cleaning fee against the actual cleaning cost and turnover frequency to see how much margin or loss each stay generates.
Open tool → tools/finance/dumpster-tonnage-estimate/Dumpster Rental Tonnage Overage Estimator
Estimate dumpster rental weights and overage charges: choose a container size, enter expected waste volume or load weight, and see the overage tonnage and its cost.
Open tool → tools/finance/ebay-seller-profit/eBay Seller Profit & Insertion Fee Calculator
Compute eBay seller take-home profit from sale price, insertion fees, final value fees, payment processing, shipping and cost of goods, with net profit and margin.
Open tool → tools/finance/upwork-vs-fiverr-pay/Upwork vs Fiverr Take-Home Pay Splitter
Compare freelance marketplace take-home pay: enter a project rate and see net pay after Upwork and Fiverr platform and processing fees, and which returns more.
Open tool → tools/finance/wise-vs-ofx-wire/Wise vs OFX Cross-Border Wire Cost Tool
Compare cross-border transfer costs for Wise and OFX: amount, FX margin, transfer and receive fees, plus total cost and the amount received in the target currency.
Open tool → tools/finance/ecom-return-rate-impact/E-Commerce Return Rate & Profit Impact Modeler
Model how product return rate affects e-commerce profitability through units sold, price, cost of goods, return percentage and per-return restocking and shipping costs.
Open tool → tools/finance/ad-spend-roas-cac/Ad Spend ROAS & Break-Even CAC Calculator
Compute ad-spend efficiency from revenue and spend, then break-even customer acquisition cost from gross margin per sale and conversion, with an affordable-CAC figure.
Open tool → tools/finance/affiliate-commission-splitter/Affiliate Commission Payout Splitter
Split an affiliate or referral commission payout among parties after platform fees: gross commission, platform fee percentage, net per party and allocation balance.
Open tool → tools/finance/ecom-warehouse-bin-sizer/E-Commerce Warehouse Bin Storage Sizer
Size warehouse bin storage for e-commerce inventory from bin dimensions and per-SKU box carton volume, with SKU fit per bin, bins needed and wasted-space percent.
Open tool → tools/finance/fleet-lease-mileage/Fleet Vehicle Lease Mileage Overage Estimator
Estimate fleet vehicle lease mileage overage cost from allotted vs actual miles and the overage charge per mile, with projected overage and total cost over the term.
Open tool → tools/finance/cam-fee-splitter/CAM Fee Splitter
Split Common Area Maintenance charges among commercial tenants from the annual CAM pool and each tenant's area or rentable share, with prorated share and per-sq-ft rate.
Open tool → tools/finance/self-storage-yield/Self-Storage Occupancy Yield Modeler
Model occupancy percentage, gross potential and effective rent and yield per square foot for a self-storage facility, with a break-even-occupancy estimate.
Open tool → tools/finance/occupancy-revenue/Occupancy Revenue Calculator
Compute park/site occupancy revenue for an RV park or campground: sites, nightly or seasonal rates, and occupancy by period. Shows nights sold, gross occupancy revenue, and revenue per available site.
Open tool → tools/finance/propane-revenue-margin/Propane Revenue & Margin Calculator
Model propane resale revenue and margin at an RV park or campground: delivered cost per gallon, resale price, gallons sold per season, and delivery/equipment fees. Shows gross revenue, COGS, gross margin and margin percent.
Open tool → tools/finance/site-profitability/Site-Level Profitability Modeler
Model per-site profitability for an RV park or campground: monthly revenue per site and site-specific costs (utilities, maintenance, amenity/overhead share). Shows net profit per site, margin percent, and a profit-ranked list of sites.
Open tool → tools/finance/seasonal-vs-transient/Seasonal vs. Transient Revenue Splitter
Split and model seasonal versus transient revenue at an RV park or campground: seasonal contract sites and rate, transient nightly sites and rate/occupancy. Shows each stream's revenue, share percent, and blended occupancy and revenue per site.
Open tool → tools/finance/rent-increase-impact/Rent Increase Impact Calculator
Model the financial impact of a site-rate increase: current rent, occupancy elasticity to the increase, affected sites, and new rate. Shows added gross revenue, estimated lost revenue, net income impact, and break-even occupancy for the increase.
Open tool → tools/finance/occupancy-breakeven/Park Occupancy Break-Even Calculator
Find the occupancy percentage an RV park or campground needs to break even: fixed costs, variable cost per occupied site-night, and revenue per occupied site. Shows break-even occupancy %, break-even site-nights, and margin at target occupancy.
Open tool → tools/finance/mortgage-points-breakeven/Mortgage Points Break-Even Calculator
Decide if mortgage discount points are worth it: payment at each rate, monthly savings and months to break even.
Open tool → tools/finance/mortgage-term-comparison/15/20/30-Year Mortgage Term Comparison
Compare 15, 20 and 30-year fixed mortgages side by side - payment, total interest and true cost.
Open tool → tools/finance/biweekly-mortgage-savings/Biweekly Mortgage Payment Savings Calculator
Model biweekly payments: months shaved off the term, interest saved and the payoff date.
Open tool → tools/finance/arm-vs-fixed-mortgage/ARM vs. Fixed-Rate Mortgage Comparison
Compare an ARM against a fixed loan year by year, including the worst-case rate scenario.
Open tool → tools/finance/multi-loan-comparison/Multi-Loan Comparison Calculator
Compare any set of loan offers - payment, total interest and true cost with fees applied.
Open tool → tools/finance/credit-card-min-payment-payoff/Credit Card Minimum-Payment Payoff Calculator
See how long minimum payments take to clear a balance, plus what extra payments save.
Open tool → tools/finance/business-breakeven/Business Break-Even Calculator
Fixed costs, price and variable cost per unit become break-even units and revenue.
Open tool → tools/finance/profit-margin-markup/Profit Margin & Markup Calculator
Move freely between cost, price, margin and markup - enter any two, see all four.
Open tool → tools/finance/business-cash-flow/Business Cash Flow Calculator
Project 12 months of cash flow from recurring and one-off items, flagging low months.
Open tool → tools/finance/financial-ratios/Financial Ratios Calculator
Current, quick, debt-to-equity, margins and return ratios with plain-language readings.
Open tool → tools/finance/working-capital-needs/Working Capital Needs Calculator
Turn collection, inventory and payables days into the working capital your cycle needs.
Open tool → tools/finance/dscr-calculator/Debt Service Coverage Ratio (DSCR) Calculator
DSCR from net operating income and a full debt schedule, with maximum supportable service.
Open tool → tools/finance/checkbook-balancer/Checkbook Balancer
Reconcile against the statement with a live ledger - totals and difference to match to zero.
Open tool → tools/finance/home-budget-calculator/Home Budget Calculator
Monthly household budget: category totals, surplus or deficit and where the money goes.
Open tool → tools/finance/student-budget-calculator/Student Budget Calculator
Plan a semester - billed costs, living costs and income sources down to a weekly view.
Open tool → tools/finance/tvm-calculator/TVM (Time Value of Money) Calculator
Solve for any of PV, FV, payment, periods or rate - lumpsums and annuities alike.
Open tool → tools/finance/effective-interest-rate/Effective Interest Rate Calculator
Convert a nominal rate into the true EAR, with or without fees, at your compounding.
Open tool → tools/finance/cpi-inflation-calculator/CPI / Inflation Adjustment Calculator
Adjust any dollar amount between two years with editable CPI data - forward and back.
Open tool → tools/finance/capm-calculator/CAPM Calculator
Expected return from risk-free rate, beta and market premium, with a beta sensitivity table.
Open tool → tools/finance/stock-return-calculator/Stock Return Calculator
Gordon growth, multi-stage DDM and historical CAGR - three return models in one tool.
Open tool → tools/finance/wacc-calculator/WACC Calculator
Weighted average cost of capital from equity and debt weights, with a mix sensitivity view.
Open tool → tools/finance/black-scholes-calculator/Black-Scholes Option Calculator
Price a European call or put and see the full Greeks, intrinsic value and moneyness.
Open tool →Multi-City World Clock
Compare the current local time in 7 world cities side by side, automatically updated.
Open tool → tools/dates/seconds-alive/Seconds Alive
Your exact age in seconds, plus milestone dates like your 1 billionth second.
Open tool → tools/dates/date-difference/Date Difference Calculator
Calculate the exact number of days, weeks and months between any two dates.
Open tool → tools/dates/age-calculator/Age Calculator
Compute precise age in years, months and days from date of birth.
Open tool → tools/dates/date-add-subtract/Date Add / Subtract Calculator
Add or subtract days, weeks, months and years from a given date.
Open tool → tools/dates/business-days/Business Days Calculator
Count working days between two dates, excluding weekends and holidays.
Open tool → tools/dates/countdown/Countdown Calculator
Count down to any future date with days, hours, minutes and seconds.
Open tool → tools/dates/week-number/Week Number Calculator
Determine the ISO week number for any date and find which week a date falls in.
Open tool → tools/dates/time-duration/Time Duration / Elapsed Time Calculator
Calculate elapsed time between two timestamps with hours, minutes and seconds.
Open tool → tools/dates/timezone-difference/Time Zone Difference Calculator
Compare time zones between two cities using manual UTC offsets — no network required.
Open tool → tools/dates/day-of-week/Day of the Week Calculator
Find out what day of the week any date falls on with instant calculation.
Open tool →Image Compressor
Compress and resize images locally in your browser with instant size and quality feedback.
Open tool → tools/media/svg-cleaner/SVG Cleaner / Optimizer
Clean, deduplicate and optimize SVG markup with a live before-and-after preview.
Open tool → tools/finance/debt-snowball-avalanche/Debt Snowball vs Avalanche
Compare snowball and avalanche payoff strategies month by month with real interest math.
Open tool → tools/trade/paint-coverage-calculator/Paint Coverage Calculator
Work out paint needed per room from wall area, coat count and waste factor.
Open tool → tools/dev/port-protocol-lookup/Port & Protocol Lookup
Look up well-known ports and protocols instantly with service hints and references.
Open tool → tools/dev/rate-limit-header-parser/Rate-Limit Header Parser
Decode RateLimit/Limit/Reset headers into human-readable windows and retry advice.
Open tool → tools/media/archive-unzipper/In-Browser Archive Unzipper
Open zip archives locally, preview entries and extract only the files you need.
Open tool → tools/media/font-converter/Font File Converter
Convert fonts between woff2, woff, ttf and otf locally with subsetting options.
Open tool → tools/media/heic-converter/HEIC/HEIF to JPEG/PNG Converter
Convert iPhone HEIC photos to JPEG or PNG right on your device — no uploads.
Open tool → tools/media/gpx-visualizer/GPX/KML Route + Elevation Visualizer
Plot GPX and KML routes on an interactive map with elevation profiles and stats.
Open tool → tools/media/image-resizer-crop-studio/Image Resizer & Crop Studio
Crop and resize images with aspect-ratio locks and export PNG/JPEG/WebP at chosen quality.
Open tool → tools/media/palette-extractor/Palette Extractor
Extract dominant colors from any image into swatches with copyable CSS variables.
Open tool → tools/media/aspect-ratio-calculator/Aspect Ratio Calculator
Solve dimensions from ratios and back, with presets and fit-within-bounds sizing.
Open tool → tools/media/pdf-splitter-merger/PDF Splitter / Merger
Split a PDF into individual pages or ranges and merge multiple PDFs together — fully client-side.
Open tool → tools/media/audio-pitch-speed/Audio Pitch/Speed Shifter
Shift an audio clip's pitch and speed in the browser via the Web Audio API and export the processed result.
Open tool → tools/media/video-to-gif/Video-to-GIF Converter
Convert an uploaded video segment into an animated GIF at a chosen size and frame rate, entirely client-side.
Open tool → tools/media/screen-recorder/Screen / Webcam Recorder
Record your screen or camera via MediaRecorder and download the file — client-side only, nothing leaves the browser.
Open tool → tools/media/ocr-text-extractor/OCR Text Extractor
Drop an image and get the text — the engine, language model and worker are embedded, so nothing is uploaded or fetched.
Open tool → tools/media/speech-to-text/Speech-to-Text Transcriber
Transcribe an uploaded audio file to text on-device — no external API, everything stays local in the browser.
Open tool → tools/media/text-to-speech/Text-to-Speech Generator
Turn typed text into spoken audio with voice, rate and pitch controls via the browser's speech synthesis.
Open tool → tools/media/batch-watermarker/Batch Watermarker
Stamp text or an image watermark across many images at once with position, opacity and size controls.
Open tool → tools/media/audio-waveform/Audio Waveform Generator
Render a visual waveform from an audio file by decoding it client-side and plotting amplitude over time.
Open tool → tools/media/pdf-password-tool/PDF Password Removal & Encryption
Lock a PDF with a user/owner password or unlock one you supply the password for — fully client-side crypto.
Open tool → tools/media/image-bg-remover/Image Background Remover
Remove the background from an image on-device and export it with transparency.
Open tool → tools/media/svg-rasterizer/SVG to High-Res Canvas Rasterizer
Rasterize an SVG to a sharp, high-resolution PNG at a chosen scale using the canvas.
Open tool → tools/media/audio-normalizer/Audio Noise Gate & Normalizer
Apply a noise gate and normalize loudness to a target level on an audio clip via the Web Audio API.
Open tool → tools/media/video-subtitle-sync/Video Subtitle Sync/Format Converter
Parse, re-time and convert subtitle files (SRT/VTT) between formats and validate reading speed.
Open tool → tools/media/youtube-thumb-contrast/YouTube Thumbnail WCAG Contrast Checker
Check that a YouTube thumbnail's text and subject meet readable contrast: enter background/subject and text colors, then compute the WCAG contrast ratio and pass/fail for normal text, large text and UI components, with guidance for small-size readability. Zero uploads, fully offline.
Open tool →Data Sanitizer
Scan logs and freeform text for sensitive values — emails, phones, SSNs, card numbers and more — then mask or redact them on-device.
Open tool → tools/privacy/diff-merge-studio/Diff & Merge Studio
Compare two texts side by side and merge selected changes with full local processing.
Open tool → tools/privacy/favicon-suite/Favicon & App Icon Suite
Generate complete favicon and app-icon sets with manifest snippets from a single image.
Open tool → tools/privacy/aes-file-encryption/AES-256-GCM In-Browser File Encryption
Encrypt or decrypt any file with AES-256-GCM and a passphrase — nothing leaves the tab.
Open tool → tools/privacy/totp-generator/TOTP/HOTP Two-Factor Code Generator
Generate two-factor codes from a secret locally, with live countdown windows.
Open tool → tools/privacy/log-file-redactor/Log File Redactor
Scrub IPs, credentials and identifiers from log files with rule presets and an audit view.
Open tool → tools/privacy/export-scrubber/Slack/Discord Export Scrubber
Clean chat exports of personal messages and attachments before sharing or archiving.
Open tool → tools/privacy/resume-pii-stripper/Resume/PDF PII Stripper
Strip personal identifiers from resumes and PDFs so candidates stay anonymous in review.
Open tool → tools/privacy/extension-permission-auditor/Browser Extension Permission Auditor
Review extension permissions and flag risky combinations before you install anything.
Open tool → tools/privacy/har-secrets-scanner/HAR File Secrets Scanner
Scan HAR captures for tokens, cookies and auth headers before archiving or sharing.
Open tool → tools/privacy/password-strength-auditor/Password Strength Auditor
Score password strength fully offline — entropy, common patterns and crack-time estimates.
Open tool → tools/privacy/password-entropy-calculator/Password Entropy Calculator
Compute password entropy in bits with pool-size math - fully offline.
Open tool → tools/privacy/email-header-analyzer/Email Header Analyzer
Parse email headers into a routing timeline with SPF/DKIM/DMARC verdicts and redaction.
Open tool → tools/privacy/cookie-tracker-scanner/Cookie / Tracker Scanner
Scan a page for the cookies and trackers it sets or depends on, listing cookie names, domains, expiry and third-party trackers. Runs client-side.
Open tool → tools/privacy/json-pii-scanner/JSON PII Scanner
Paste a JSON document and detect PII fields by key-name heuristics and nested-field traversal, with a redacted view for review.
Open tool → tools/privacy/sql-dump-sanitizer/SQL Dump Sanitizer
Sanitize PII in a pasted SQL dump or INSERT VALUES clause while preserving structure, producing a masked copy for safe sharing.
Open tool → tools/privacy/pseudonymization-tool/Pseudonymization Tool
Replace repeated sensitive values with consistent fake replacements so the same input maps to the same output, with a mapping table.
Open tool →Gravel Driveway Calculator
Estimate tons, cubic yards and delivered cost of gravel for a driveway from its length, width and depth.
Open tool → tools/trade/asphalt-paving-calculator/Asphalt Paving Tonnage & Cost Modeler
Calculate hot-mix asphalt tonnage from area and compacted thickness, priced by local per-ton rates.
Open tool → tools/trade/drywall-estimator/Drywall Sheet Count Estimator
Estimate sheet counts, screws, tape and joint compound for walls and ceilings with waste allowance.
Open tool → tools/trade/lumber-board-feet-calculator/Lumber Board Feet Optimizer
Total board feet and cost for a lumber list, optimized across standard stock lengths to reduce offcuts.
Open tool → tools/trade/turf-sod-calculator/Turf & Sod Coverage Estimator
Work out sod rolls or seed coverage for lawns of any shape, including waste factor and pallet counts.
Open tool → tools/trade/mulch-yardage-calculator/Mulch Cubic Yardage Calculator
Convert bed dimensions into cubic yards or bags of mulch at your target depth, with delivery pricing.
Open tool → tools/trade/tile-grout-calculator/Tile & Grout Coverage Calculator
Compute tile count and grout volume from room size, tile format and joint width, plus overage buffer.
Open tool → tools/trade/insulation-rvalue-calculator/Attic Insulation R-Value Calculator
Determine required R-value and material thickness by climate zone, comparing batts, blown-in and spray foam.
Open tool → tools/trade/fence-post-calculator/Fence Post Spacing Calculator
Space fence posts evenly across any run, with post, rail and concrete quantities for the whole job.
Open tool → tools/trade/concrete-volume-calculator/Concrete Volume Calculator
Slab, footing, column and pad concrete volumes in yards or meters with bag counts and waste %.
Open tool → tools/trade/roof-pitch-shingle-calculator/Roof Pitch & Shingle Calculator
Pitch-adjusted roof area from building footprint with shingle squares, bundles and underlayment rolls.
Open tool → tools/trade/wallpaper-calculator/Wallpaper Rolls Calculator
Roll counts from wall area minus openings, with pattern-repeat drop matching and waste allowance.
Open tool → tools/trade/video-production-dayrate/Video Production Day Rate & OT Calculator
Calculate day rates, overtime and crew costs for video production shoots.
Open tool → tools/trade/cnc-feed-speed/CNC Router Feed & Speed Calculator
Optimize feed rate, spindle speed and chip load for CNC routing operations.
Open tool → tools/trade/filament-weight-cost/3D Printing Filament Cost Converter
Convert filament weight to cost based on spool price, density and print volume.
Open tool → tools/trade/hydraulic-cylinder/Hydraulic Cylinder Calculator
Compute force, speed and bore/rod dimensions for hydraulic cylinder sizing.
Open tool → tools/finance/generic-loan/Generic Loan Calculator
Calculate monthly payment, total interest and amortization for auto, personal, business or other loans.
Open tool → tools/finance/mortgage-payment/Mortgage Payment Calculator
Compute monthly payment, total interest and amortization schedule from principal, rate and term.
Open tool → tools/finance/house-affordability/House Affordability Calculator
Determine maximum home price based on income, debts, down payment and interest rate.
Open tool → tools/finance/debt-to-income/Debt-to-Income Ratio Calculator
Calculate front-end and back-end DTI ratios from monthly debt payments and gross income.
Open tool → tools/finance/rent-vs-buy/Rent vs. Buy Calculator
Compare total cost of renting vs buying over a time horizon with mortgage, rent and opportunity cost.
Open tool → tools/finance/down-payment/Down Payment Calculator
Calculate down payment amount, monthly payment and PMI cost based on home price and percentage.
Open tool → tools/finance/irr-calculator/IRR Calculator
Calculate Internal Rate of Return from a series of cash flows with multiple periods.
Open tool → tools/finance/bond-calculator/Bond Calculator
Calculate bond price, yield to maturity, current yield and coupon rate for zero-coupon and coupon bonds.
Open tool → tools/finance/payback-period/Payback Period Calculator
Calculate payback period for an investment with annual cash flows and cumulative cash flow chart.
Open tool → tools/dev/password-generator/Password Generator
Generate strong random passwords with configurable length, character sets and real-time strength indicator.
Open tool → tools/dev/docker-run-compose/Docker Run ↔ Compose Converter
Convert Docker run commands to docker-compose.yml and vice versa with full flag support.
Open tool → tools/dev/unit-converter/Generic Unit Converter
Convert between length, weight, temperature, data storage, speed and pressure units interactively.
Open tool → tools/dev/json-keypath/JSON Key-Path Extractor/Flattener
Flatten nested JSON to dot-notation key paths or extract values by key path with array support.
Open tool → tools/dev/xml-diff/XML Diff Tool
Compare two XML documents and highlight added, removed and modified nodes.
Open tool → tools/dev/yaml-diff/YAML Diff Tool
Compare two YAML documents with proper YAML parsing and highlighted differences.
Open tool → tools/privacy/quick-crypto/Quick Encrypt/Decrypt Text
AES encryption and decryption with passphrase, fully client-side with no server calls.
Open tool → tools/dev/ipv4-decimal/IPv4 ↔ Decimal Converter
Convert between dotted-decimal IPv4 notation and integer representation with subnet support.
Open tool → tools/quick/scratch-pad/Scratch Pad
Temporary notepad with auto-save to localStorage, word count and distraction-free interface.
Open tool → tools/finance/capital-gains-tax/Capital Gains Tax Calculator
Estimate capital gains tax on asset sales with short-term vs long-term rate calculations.
Open tool → tools/finance/depreciation-calculator/Depreciation Calculator
Calculate straight-line depreciation for assets with salvage value and useful life.
Open tool → tools/finance/cagr-calculator/CAGR Calculator
Compute Compound Annual Growth Rate from beginning value, ending value and years.
Open tool → tools/finance/savings-interest/Savings Interest Calculator
Calculate simple and compound interest on savings with regular contributions.
Open tool → tools/health/waist-hip-ratio/Waist-to-Hip Ratio Calculator
Calculate waist-to-hip ratio and assess cardiovascular health risk category.
Open tool → tools/health/heart-rate-zones/Heart Rate Zones Calculator
Calculate target heart rate training zones based on age and maximum heart rate.
Open tool → tools/health/vo2-max-estimator/VO2 Max Estimator
Estimate your VO2 max from age, resting heart rate and fitness test results.
Open tool → tools/health/running-pace/Running Pace Calculator
Calculate pace, speed or distance from two of the three inputs for any run.
Open tool → tools/health/daily-water-intake/Daily Water Intake Calculator
Calculate recommended daily water intake based on weight, activity and climate.
Open tool → tools/health/lean-body-mass/Lean Body Mass Calculator
Estimate lean body mass from weight, height, age and gender using multiple formulas.
Open tool → tools/health/ideal-weight-range/Ideal Weight Range Calculator
Find a healthy weight range using multiple formula methods for your height and build.
Open tool → tools/health/blood-pressure-category/Blood Pressure Category Calculator
Classify blood pressure readings into category ranges. Informational, not medical advice.
Open tool → tools/health/body-surface-area/Body Surface Area Calculator
Calculate body surface area using the Mosteller and Du Bois formulas.
Open tool → tools/health/max-heart-rate/Maximum Heart Rate Calculator
Estimate maximum heart rate using age-based and formula-comparison methods.
Open tool → tools/health/bmi-calculator/BMI Calculator
Calculate body mass index from height and weight and see the category range.
Open tool → tools/health/bmr-tdee/BMR / TDEE Calculator
Estimate basal metabolic rate and total daily energy expenditure by activity level.
Open tool → tools/health/life-expectancy-calculator/Life Expectancy Calculator
Estimated remaining years from base tables and lifestyle factors - informational only, not medical advice.
Open tool → tools/finance/roi-calculator/ROI Calculator
Compute return on investment, gain, and ROI percentage from cost and current value.
Open tool → tools/finance/yield-calculator/Yield Calculator
Calculate current yield and yield to maturity for bonds from price, coupon and term.
Open tool → tools/finance/debt-payoff/Debt Payoff Calculator
Compute payoff time, total interest and amortization schedule for a single debt.
Open tool → tools/trade/grease-trap-scheduler/Grease Trap Maintenance Scheduler
Schedule grease trap and grease interceptor pumping from trap capacity and food-service FOG load, with recommended interval and next service date.
Open tool → tools/trade/food-truck-breakeven/Food Truck Break-Even Calculator
Model food truck fixed versus variable costs and find the units and monthly revenue needed to break even at a given average sale.
Open tool → tools/trade/septic-pumping-schedule/Septic Tank Pumping Schedule Calculator
Estimate septic tank pump-out intervals from tank capacity, occupants and daily flow, with recommended years-months and next service due date.
Open tool → tools/trade/dental-hygienist-splitter/Dental Hygienist Production Splitter
Split dental practice hygiene production and commission across hourly or production-based comp plans, with net payout after cost shares and effective rate.
Open tool → tools/trade/trucking-fuel-toll/Trucking Fuel/Toll Estimator
Estimate truck route fuel and toll cost from route miles, fuel economy, diesel price and toll segments, with per-route and per-mile totals.
Open tool → tools/trade/home-inspector-report/Home Inspector Report Builder
Build a structured home inspection report with system checklists, defect and note statusing, and a printable summary for client handoff.
Open tool → tools/trade/salon-tip-pooling/Salon Tip Pooling Splitter
Split pooled tips among salon or service-industry staff by hours or service points, with even-split mode and an allocation balance check.
Open tool → tools/trade/commercial-laundry-dosing/Commercial Laundry Chemical Dosing Calculator
Calculate chemical dosing for commercial laundry machinery: per-cycle dose and daily, weekly & monthly usage and cost for detergent, sanitizer, sour and softener.
Open tool → tools/trade/hoa-special-assessment/HOA Special Assessment Calculator
Allocate an HOA/condo special assessment fairly across owners by unit, square footage or ownership percentage, and compare lump-sum vs installment payment plans.
Open tool → tools/trade/laundry-coin-vs-card/Laundry Room Coin-vs-Card ROI
Compare coin vs card payment for a laundromat's machines: monthly net revenue per method and the card system's years-to-payback from fees and handling costs.
Open tool → tools/trade/parking-garage-revenue/Parking Garage Revenue-per-Space
Model a parking garage's monthly and annual revenue, revenue per available space and utilization-rate impact on yield from rented and transient spaces.
Open tool → tools/trade/irrigation-zone-gpm/Irrigation Zone GPM Calculator
Calculate flow (GPM) per irrigation zone from zone area, head type, spacing and precipitation rate, with head count and a valve/pipe sizing note.
Open tool → tools/trade/generator-sizing/Generator Sizing Calculator
Size a backup or portable generator from appliance running watts and start/surge watts, showing total continuous load and required surge capacity.
Open tool → tools/trade/contractor-change-order/Contractor Change-Order Markup Calculator
Price a construction change order from added labor and materials plus overhead & profit markup, optional GC fee and deleted-scope credit, and update the running contract total.
Open tool → tools/trade/concrete-rebar-spacing/Concrete Slab Rebar Spacing & Mesh Grid Tool
Design rebar or wire-mesh layout for a concrete slab: number of bars each direction, total bar lengths and weight, lap overlap and a welded-wire-mesh alternative.
Open tool → tools/trade/retaining-wall-calculator/Retaining Wall Block & Backfill Calculator
Estimate retaining-wall materials: blocks per course and total, caps, base gravel, drain-rock backfill volume and cost from wall length and height.
Open tool → tools/trade/car-hauler-axle-balancer/Car Hauler Trailer Axle Weight Balancer
Calculate axle weight distribution, tongue and kingpin load for a car-hauler or equipment trailer, checking each axle and the rig against GVWR/GAWR ratings.
Open tool → tools/trade/gas-burner-btu-sizer/Atmosphere Gas Burner BTU & Nozzle Sizer
Size an atmospheric gas burner and its orifice or nozzle from desired BTU output, gas type, supply pressure and orifice diameter for burner service or furnace applications.
Open tool → tools/trade/solar-battery-sizing/Solar Battery Storage Bank Sizing Tool
Size an off-grid battery bank from daily kWh, autonomy days, system voltage and battery chemistry, showing required bank kWh, battery count and series/parallel layout.
Open tool → tools/trade/ev-fleet-charging/EV Fleet Charging Demand Sizer
Model EV fleet charging power and energy demand: daily fleet kWh, simultaneous kW demand, required charging stations and energy cost from vehicles, mileage and charge rates.
Open tool → tools/finance/str-occupancy-yield/Short-Term Rental Occupancy Yield Modeler
Model occupancy and yield for an STR property: occupancy percent, gross and net revenue, revenue per available night and break-even occupancy from rates, nights and costs.
Open tool → tools/finance/marina-slip-fee/Marina Slip Rental Fee & Utility Pass-Through
Price marina boat-slip rental with utility pass-through: per-slip monthly fee, total monthly and yearly marina revenue, and the utility pass-through share.
Open tool → tools/trade/cold-storage-thermal-loss/Cold Storage Thermal Load Estimator
Estimate refrigeration heat load for a cold-storage room from area, insulation R-value and temperature difference, giving heat leak in BTU/hr and tons of refrigeration.
Open tool → tools/finance/freight-ltl-ftl-threshold/Freight LTL vs. FTL Rate Threshold
Compare less-than-truckload vs full-truckload freight to find the break-even weight at which switching shipping modes becomes cheaper from weight, class rates and accessorials.
Open tool → tools/trade/pallet-rack-capacity/Pallet Rack Capacity & Deflection Modeler
Model pallet-rack beam and upright capacity: per-level load, deflection estimate and total rack capacity with a safety factor, checking configuration against rated limits.
Open tool → tools/trade/event-tent-sizer/Event Tent Square Footage & Capacity Sizer
Size an event tent from guest count and occupancy type, giving total required square footage, a recommended tent size and the resulting seating layout.
Open tool → tools/trade/commercial-hvac-sizing/Commercial HVAC Tonnage & CFM Quick Sizing
Size a commercial HVAC system from area, ceiling height, occupants and space heat load: recommended tonnage, supply CFM, and equipment-capacity guidance.
Open tool → tools/trade/grain-bin-storage/Grain Bin Bushel Storage & Moisture Tool
Estimate grain bin bushel capacity and moisture shrink from bin dimensions and grain type, giving usable storage, dry tons and shrink percent.
Open tool → tools/trade/brewery-plato-sg/Brewery Batch Plato-to-Specific-Gravity Tool
Convert brewery gravity between degrees Plato and specific gravity, with points, estimated ABV and gravity drop for a batch.
Open tool → tools/trade/winery-barrel-yield/Winery Oak Barrel Toast Yield & Cost Calculator
Model winery oak-barrel costs and yields: cost per bottle and barrel, usable yield after aging loss, and replacement schedule cost.
Open tool → tools/trade/coffee-roast-weight-loss/Coffee Roaster Batch Weight Loss Estimator
Estimate coffee-roasting weight loss and yield from green batch weight and roast level, giving roasted yield and cost per roasted pound.
Open tool → tools/health/commercial-pool-chemical/Commercial Swimming Pool Chemical Doser
Calculate chemical dosing for a commercial pool from volume and target-vs-current readings for chlorine, pH, alkalinity and cyanuric acid.
Open tool → tools/trade/hvac-duct-pressure/HVAC Duct Static Pressure & CFM Calculator
Size ductwork for static pressure and airflow: velocity, pressure drop per 100 ft, total static pressure rise and equivalent duct size.
Open tool → tools/trade/well-pump-flow-lift/Water Well Pump Flow Rate & Lift Modeler
Model well pump flow and lift: total dynamic head, required hydraulic horsepower and recommended pump discharge sizing.
Open tool → tools/trade/livestock-pasture-aum/Livestock Pasture AUM Tool
Calculate pasture stocking capacity in animal-unit-months from acreage, forage production, intake and utilization rate.
Open tool → tools/trade/irrigation-drip-flow/Irrigation Drip Line Flow & Pressure Drop Tool
Size a drip irrigation line: total flow, pressure drop per 100 ft, end-of-line pressure and whether emitters stay in spec.
Open tool → tools/trade/timber-cruise-calculator/Timber Cruise Calculator — Board Feet & Stumpage
Estimate standing timber volume (Doyle and Scribner scales), board feet per acre, total MBF and stumpage value from forest cruise data: DBH, merchantable height, plot scale and stumpage price per thousand board feet.
Open tool → tools/trade/electrical-load-estimator/30A/50A Electrical Load Estimator
Estimate RV park / campground electrical load per site and at the service: 30A and 50A sites, connected loads, and diversity/demand factors. Shows per-site demand, peak park demand, and recommended service or transformer capacity in Amps/kVA.
Open tool → tools/dev/pretty-print-studio/Pretty-Print Studio — JS / CSS / HTML Beautifier
Format or minify JavaScript, CSS and HTML in either direction: beautify pasted code into readable indented output or compact it back down, with live byte-size stats and per-language formatting.
Open tool → tools/dev/file-base64-converter/File ↔ Base64 Converter
Convert any file to a base64 data URI or decode a base64 string back to the original file for download, with strict validation and binary-safe image preview.
Open tool → tools/privacy/ai-upload-privacy-checker/AI Upload Privacy Checker
Drop in a document file and scan it for emails, phones, SSNs, Luhn-valid credit cards and API-key patterns before you upload it anywhere. In-place redaction and cleaned-file download, everything stays local.
Open tool → tools/finance/solar-roi-calculator/Solar Panel ROI Calculator
Estimate annual generation and savings from panel size and local insolation, then model degradation, incentives and inverter cost through 25 years of cumulative cash flow, simple payback, ROI and IRR.
Open tool → tools/finance/rent-per-sqft-annualizer/Commercial Rent per Sq Ft Annualizer
Annualize lease terms quoted in dollars per square foot with a load factor and NNN add-backs, showing base, full-service and per-square-foot rent plus a term schedule.
Open tool → tools/trade/mini-split-btu-sizer/Multi-Zone Ductless Heat Pump BTU Sizer
Size a ductless mini-split across multiple rooms: per-zone cooling and heating BTUs, recommended indoor head sizes, and an outdoor-unit selection with a heads-to-outdoor combination-ratio check.
Open tool → tools/finance/etsy-shopify-fees/Etsy & Shopify Fee & Margin Calculator
Compare take-home profit and margin for Etsy and Shopify sellers: fees, shipping, listing and payment-processing, plus the Shopify orders needed to cover the monthly plan.
Open tool →Ohm's Law Calculator
Enter any two of voltage (V), current (I) and resistance (R) to compute the third using Ohm's Law. Clear fields and try another combination instantly.
Open tool → tools/science/quadratic-formula/Quadratic Formula Calculator
Solve ax2 + bx + c = 0 - real or complex roots, vertex, axis of symmetry and a value table.
Open tool →Meta Tag Generator
Generate the essential meta tag block for any page: title, description, canonical, robots directives and theme metadata, with live length guidance and copy-ready HTML output.
Open tool → tools/marketing/open-graph-generator/Open Graph Generator & Preview
Build the Open Graph meta block for Facebook/LinkedIn sharing with a live social-card preview, recommended-length checks and one-click copy of the finished og: tags.
Open tool → tools/marketing/twitter-card-generator/Twitter Card Generator
Generate the twitter: card meta tags for X/Twitter sharing with a live card preview, handle normalization and copy-ready HTML output.
Open tool → tools/marketing/utm-builder/UTM Campaign URL Builder
Build clean campaign tracking URLs: set source, medium, name and optional term or content, and get a correctly merged, URL-encoded tracking link with a parameter breakdown.
Open tool → tools/marketing/robots-txt-generator/Robots.txt Generator
Create a robots.txt from a guided form — user-agent blocks, allow/disallow rules, crawl-delay and sitemap — with a live file preview, validation warnings and download.
Open tool → tools/marketing/xml-sitemap-generator/XML Sitemap Generator
Turn a pasted list of URLs into a valid sitemap.xml with lastmod, changefreq and priority columns, XML escaping and dedupe. No crawling — everything comes from your paste.
Open tool → tools/marketing/url-slug-generator/URL Slug Generator
Convert any title into a clean URL slug with lowercase, separator, diacritic-folding, stopword and length options, plus a live output preview and copy.
Open tool → tools/marketing/keyword-density-checker/Keyword Density Checker
Analyze pasted text locally for keyword frequency and density, 1-, 2- and 3-word phrases, stopword toggles and over-optimization flags. Nothing leaves the browser.
Open tool → tools/marketing/serp-snippet-preview/SERP Snippet Preview Simulator
Simulate how a page appears in Google search results — title, URL and description with realistic truncation, character guidance and desktop/mobile preview widths.
Open tool → tools/marketing/hreflang-tag-generator/hreflang Tag Generator
Generate hreflang annotations for multilingual sites — link rel=alternate tags and Link HTTP header lines — with code validation and duplicate detection.
Open tool →HTTP Status Codes - Quick Reference
Every HTTP status code from 100 to 511 with what each means and what the client or server should do - searchable and copy-ready.
Open tool → tools/reference/html-cheat-sheet/HTML - Quick Reference
Semantic elements and attributes used every day: document structure, media, forms, tables and accessibility.
Open tool → tools/reference/css-cheat-sheet/CSS - Quick Reference
Selectors, the box model, layout, typography and effect properties that do the real work in modern CSS.
Open tool → tools/reference/javascript-cheat-sheet/JavaScript - Quick Reference
Language primitives, DOM operations, async patterns and the pitfalls that matter in vanilla JS.
Open tool → tools/reference/regular-expression-cheat-sheet/Regular Expression - Quick Reference
Regex tokens, groups, lookarounds, flags and copy-ready patterns for email, URL, UUID, color and phone.
Open tool → tools/reference/git-cheat-sheet/Git - Quick Reference
Config, workflow, branching, undo, remotes and recovery tactics - the Git commands that cover almost every situation.
Open tool → tools/reference/sql-cheat-sheet/SQL - Quick Reference
Statements, filtering, joins, aggregations and modern constructs across the common SQL dialects.
Open tool → tools/reference/bash-cli-cheat-sheet/Bash & CLI - Quick Reference
Navigation, files, text processing, processes, networking and shell tricks for everyday terminal work.
Open tool → tools/reference/markdown-cheat-sheet/Markdown - Quick Reference
Headings, emphasis, lists, links, tables, code blocks and GitHub extensions in one glanceable table.
Open tool → tools/reference/json-api-cheat-sheet/JSON API Design - Quick Reference
HTTP verbs, status conventions, REST shape, payload discipline and security defaults for JSON APIs.
Open tool →