Developer Tools

Paste 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.

Check 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.

Paste 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.

Turn 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.

Save any sheet of an Excel workbook as a CSV file, with the delimiter you need and the values exactly as Excel shows them. Your workbook is converted in your browser and never uploaded.

Turn CSV files into a proper Excel workbook: numbers you can add up, leading zeros kept, a bold header row that stays visible, and one sheet per file. Everything happens in your browser.

See 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.

Convert 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.

Make any text safe to put in a URL. Encode a single query value or path segment, or a whole URL with spaces and non-English characters, and inspect its parts.

Turn unreadable links full of %20, %3A and %2F back into plain text. See every query parameter decoded, and get a clear warning when an escape is broken.

Paste 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.

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

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

Shrink 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.

Write 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.

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

Paste one UUID or a whole list to check whether each is valid — with the exact reason when it isn't, plus its version, variant, embedded time and normalized form.

Get 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.

Calculate 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.