Developer Tools

14 free tools, ready to use

Everyday developer utilities that open instantly: format and validate JSON, test regular expressions, decode JWTs, minify code, generate UUIDs and hashes, and convert between data formats — all locally in your browser.

JSON FormatterPaste messy or minified JSON to get clean, indented output instantly — or minify it for production. Sort keys, browse a collapsible tree and see exactly where any error is.Open tool →

JSON ValidatorCheck whether your JSON is valid and get the exact line, column and reason for any error. One click repairs common mistakes like trailing commas, single quotes and comments.Open tool →

Base64 Encoder/DecoderConvert text or any file to Base64, or decode Base64 back to readable text or the original file. Handles UTF-8, URL-safe base64url and data URLs.Open tool →

Regex TesterWrite a regular expression and see every match highlighted as you type, with capture groups, named groups and a live replace preview — using your browser's real JavaScript regex engine.Open tool →

HTML MinifierMake HTML pages smaller without breaking them. Comments and extra whitespace are removed, while <pre>, <textarea>, attribute values and conditional comments stay exactly as written.Open tool →

CSS MinifierCompress your stylesheets for faster pages. CSSO removes whitespace and comments, shortens values like #ffffff to #fff and can merge duplicate rules safely.Open tool →

JS MinifierShrink JavaScript for production with Terser — the same minifier used by webpack, Vite and Next.js. See exactly how many bytes you save, before and after gzip.Open tool →

JWT DecoderPaste a JSON Web Token to read its header and claims, see whether it's expired, and optionally verify the signature with a secret or public key — all without the token leaving your browser.Open tool →

UUID GeneratorCreate random version 4 or sortable version 7 UUIDs (GUIDs) instantly, format them for your code or database, and inspect any UUID you paste.Open tool →

SHA256 GeneratorGet the SHA-256 hash of any text or file in hex or Base64, sign messages with HMAC-SHA256, and verify a download against its published SHA-256 checksum.Open tool →

MD5 GeneratorCalculate the MD5 hash of text or files of any size and check downloads against a published MD5 checksum — with SHA-1 and SHA-2 hashes alongside for comparison.Open tool →

CSV to JSONPaste CSV or open a file to get clean JSON — an array of objects or arrays — with proper handling of quotes, line breaks, delimiters and data types. Large files up to 10 MB+ work too.Open tool →

JSON to CSVTurn JSON arrays into a CSV you can open in Excel or Google Sheets. Nested objects become columns like address.city, and every value is quoted correctly.Open tool →

Timestamp ConverterSee the current Unix time, turn any epoch timestamp into a human-readable date in any time zone, or convert a date back to seconds and milliseconds.Open tool →