Online code formatters and validators
Beautify, validate, minify, and diff — across every language you touch.
Reading someone else’s minified code, committing consistent style, or shrinking output for production all come down to the same handful of operations. This workflow covers formatting, validation, and minification across HTML, CSS, JavaScript, SQL, XML, and JSON, plus a code diff for comparing versions and a regex tester for the patterns that show up in all of them. Each runs in the browser with copy-paste output — no build step, no upload.
- 1
Format by language
Beautify HTML, CSS, JavaScript, SQL, XML, or JSON into consistent, readable style — the fastest way to understand unfamiliar or minified source.
- 2
Validate the syntax
Confirm JSON, XML, or YAML is well-formed and get the exact position of the first error before it breaks a build or a parser.
- 3
Minify for production
Strip whitespace and comments from HTML, CSS, or JavaScript to shrink what you ship.
- 4
Diff two versions
Compare a before and after side by side to see exactly what changed — useful after a format, a refactor, or a merge.
- 5
Test a regex
Build and test the regular expressions that show up across all of these formats, with live match highlighting and capture groups.
Frequently asked questions
Formatting (beautifying) adds consistent indentation and line breaks to make code readable for humans. Minifying does the opposite — it strips whitespace, comments, and other non-essential characters to make the file as small as possible for production. You format while developing and minify what you ship.
No. Every formatter, minifier, and validator here runs in your browser, so the code you paste — including proprietary source — never leaves your device. That makes them safe to use on internal or unreleased code.