Developer tool
Your files never leave your device
Check your Network tab and see
Work starts the moment you drop a file
No daily limit, no sign-up, no watermark
Lookaheads, Unicode property escapes, and backreference rules match what your browser supports in RegExp. A pattern that works in grep -P may fail here. Use this to debug code that will actually run in JS, not to prototype server-side Perl.
With the global flag, all matches are listed via matchAll. Without it, you get the first match and capture groups. Invalid patterns throw with the engine error message.
No replace or split UI, no regex cookbook code generation, and no protection against catastrophic backtracking — a pathological pattern can freeze the tab. Do not paste secrets you would not put in devtools.
That is the promise behind every tool here. Files are read in your browser tab, processed there, and discarded when you close it — never uploaded to our servers.
Format, validate, prettify and beautify your JSON data instantly.
Decode JSON Web Tokens (JWT) safely to view header and payload without sending secrets to any server.
Beautify and format minified or messy JavaScript code using standard conventions.
Format, beautify, and strictly align your messy SQL queries securely.
Encode or decode query strings with encodeURIComponent — in your browser, nothing uploaded.
MD5 for checksums plus SHA-1, SHA-256, and SHA-512 via Web Crypto — all in your browser, nothing uploaded.
