Developer Tools
45 converters and calculators, sorted into 11 categories. They all run in your browser. Whatever you paste stays on your machine: nothing is uploaded, logged, or handed to analytics, and every conversion has a test suite behind it.
45 tools
Date & Time
Epoch timestamps, date/time format tokens, and cron schedules.
- Unix Timestamp Converter Convert between epoch timestamps and human dates in any timezone, at second, millisecond, microsecond, or nanosecond precision.
- Date Format Converter Translate date/time format tokens between PHP, Python, Java, Go, JavaScript, MySQL, and PostgreSQL.
- Cron Expression Translator Translate cron expressions between Unix cron, Quartz, AWS EventBridge, GitHub Actions, and Kubernetes CronJob.
- Cron Expression Explainer Get a plain-English description of a cron expression and its next 5 run times.
JSON & Data
Format, validate, convert, and generate typed models from JSON.
- JSON Formatter & Validator Format, minify, and validate JSON with inline error messages.
- JSON to TypeScript, Go, Python & Rust Turn a JSON sample into TypeScript interfaces, Go structs, Python dataclasses, or Rust serde structs.
- JSON to CSV Converter Convert a JSON array of objects to CSV, or CSV back to JSON.
- JSON String Escape / Unescape Escape raw text into a JSON string literal, or unescape one back to raw text.
Encode / Decode
Base64, URL, HTML entities, hex, and number bases.
- Base64 Encode / Decode Encode text to Base64 or decode Base64 back to text, with full UTF-8 support.
- URL Encode / Decode Percent-encode text for use in a URL, or decode it back.
- HTML Entity Encode / Decode Escape HTML special characters into entities, or decode entities back to text.
- Text to Hex Converter Convert text to hexadecimal bytes, or decode hex back to text.
- Number Base Converter Convert between binary, octal, decimal, hex, and any base 2–36, with exact 64-bit and two’s-complement views.
Hashing & IDs
Hash digests, UUID generation, and token inspection. All in-browser.
- Hash Generator (MD5, SHA-256 & more) Compute MD5, SHA-1, SHA-256, SHA-384, SHA-512, and CRC32 digests in your browser. Nothing is uploaded.
- UUID Generator & Inspector Generate UUID v4 and v7 in bulk, or paste a UUID to read its version, variant, and embedded timestamp.
- JWT Decoder Decode a JSON Web Token’s header and payload in your browser. No signature verification, and nothing reaches a server.
Text & Regex
Case conversion, slugs, counts, diffing, and regular expressions.
- Regex Tester Test a regular expression against sample text with live matches, capture groups, replace preview, and cross-engine caveats.
- Text Diff / Compare Compare two blocks of text line by line, with word-level highlighting and a copyable unified diff.
- Text Case Converter Convert text to UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, or CONSTANT_CASE.
- Slug Generator (Slugify) Turn any text into a clean, URL-safe slug. Strips accents and punctuation, and collapses spaces into hyphens.
- Word & Character Counter Count characters, words, sentences, lines, and paragraphs, with an estimated reading time.
CSS & Color
Convert CSS length units and color notations, and check contrast.
Network
IPv4 and IPv6 subnet math.
HTTP & API
Turn a cURL command into code, and build or dissect URLs.
Unit Converters
Mass, length, volume, area, speed, temperature, and digital storage.
- Unit Converters Mass, length, volume, area, speed, temperature, and digital storage, with a page for every conversion pair.
- Mass / Weight Converter Convert between kg, g, mg, metric tons, pounds, ounces, and stone.
- Length / Distance Converter Convert between meters, km, cm, mm, inches, feet, yards, and miles.
- Volume Converter Convert between liters, ml, cubic meters, gallons, cups, and more.
- Area Converter Convert between square meters, hectares, acres, and square feet.
- Speed Converter Convert between m/s, km/h, mph, and knots.
- Temperature Converter Convert between Celsius, Fahrenheit, and Kelvin.
- Digital Storage Converter Convert between bits, bytes, KB/KiB, MB/MiB, GB/GiB, and TB/TiB.
Commodity Prices
Convert a commodity price between weight and volume units.
Images
Convert and resize image files.
- SVG to PNG/JPG Converter Convert an SVG to PNG or JPG, and resize it to an exact pixel width and height.
- Image Converter (PNG, JPG, WebP, HEIC) Convert between PNG, JPG, WebP, GIF, BMP, and HEIC, and resize to an exact pixel width and height.
- PNG to JPG Converter Convert PNG to JPG online, free and instant, entirely in your browser. Resize to an exact width and height, no upload required.
- JPG to PNG Converter Convert JPG to PNG online, free and instant, entirely in your browser. Resize to an exact width and height, no upload required.
- PNG to WebP Converter Convert PNG to WebP online for a smaller, faster-loading image — free and instant, and keeps transparency. Resize while you convert.
- WebP to PNG Converter Convert WebP to PNG online, free and instant, entirely in your browser. Resize to an exact width and height, no upload required.
- JPG to WebP Converter Convert JPG to WebP online for a smaller file at the same visual quality — free and instant. Resize while you convert.
- WebP to JPG Converter Convert WebP to JPG online, free and instant, entirely in your browser. Resize to an exact width and height, no upload required.
- HEIC to JPG Converter Convert iPhone HEIC photos to JPG online, free and instant, entirely in your browser — no upload, nothing installed.
- HEIC to PNG Converter Convert iPhone HEIC photos to PNG online, free and instant, entirely in your browser — no upload, nothing installed.
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