Code Beautifier & Formatter
🔒 Runs in your browser
Four languages, one workspace
Paste or drop a file and pick the language — JavaScript, CSS,
HTML or JSON. Beautify re-indents the source across clean lines and
normalises spacing, so a one-liner scraped from a bundle, a config blob or a minified
stylesheet becomes readable again. JS, CSS and HTML are handled by the open-source
js-beautify library; JSON is re-serialised through the native parser for a
canonical, key-preserving pretty-print, with a clear message pointing at the problem when the
input is not valid JSON.
Beautify and safe minify
Minify is offered only where it can be done safely without a full tokenizer: JSON collapses to
its most compact form, and CSS is shrunk with a string-aware pass that drops comments and
redundant whitespace while leaving quoted content and significant spacing — like inside
calc() — untouched. JavaScript and HTML are intentionally left out of minify,
because hand-shrinking them without a parser risks silently breaking the code.
One caveat for JSON: numbers are re-serialised through the browser's native JSON engine, which stores them as 64-bit floats. Integers larger than 2^53 (some database or "snowflake" IDs) and very long decimals can therefore lose their last digits — keep such values as strings if exact digits matter.
Everything runs in your browser
Formatting happens entirely on your device — nothing you paste is uploaded or logged — so running a snippet straight from a production database, an API response or a private repo carries no more exposure than opening it in a local editor.
Frequently asked questions
Which languages can it format?
JavaScript, CSS, HTML and JSON. Beautify works for all four; Minify is offered for CSS and JSON, where it can be done safely.
Does my code leave the browser?
No. Formatting runs entirely on your device — nothing you paste is uploaded, stored or logged.
Is the CSS and JSON minify safe?
Yes. JSON is re-serialised through the native parser, and CSS is shrunk with a string-aware pass that keeps quoted text and calc() spacing intact.
Why can I not minify JavaScript or HTML?
Shrinking them safely needs a full parser; a naive whitespace pass can silently break the code, so those offer Beautify only.
What happens with invalid JSON?
You get a clear error message pointing at the problem instead of broken output, so you can fix the input.