Expand minified JavaScript into something you can read
Runs in your browser. Nothing you type is sent anywhere. Updated on 24 Oct 2026.A bundle from production is one line thousands of characters long. Paste it and it comes back with real line breaks, indentation and blocks you can follow, which is often enough to work out what a third-party script is doing. Variable names that a minifier shortened cannot be recovered, so expect a, b and c where the original had words.
Paste the minified bundle into JavaScript or JSX; the page opens in Beautify mode.
Read the Beautified pane, now with line breaks, indentation and blocks you can follow.
Expect short names such as a and b, because names a minifier shortened cannot be recovered.
Press Download to save the readable file, or Copy to take it to your editor.
This JavaScript formatter does the two things people want from a script file. Beautify runs Prettier over it and returns the same code laid out your way: two spaces, four spaces or a tab, semicolons or not, single or double quotes, and a line width you choose. Minify runs terser and returns the smallest equivalent file, with the size before, the size after and the percentage saved.
It suits the small jobs that interrupt a day. A snippet copied from an answer online uses a style your project does not. A file you inherited has three statements per line. You need to see roughly how big a helper will be once it ships, before deciding to write it yourself. And sometimes you need the opposite: a minified bundle expanded enough to work out what a third-party script is doing.
The tool reads plain JavaScript and JSX. TypeScript is not supported: if you paste it, the parse error would be useless, so the page checks first and tells you which TypeScript construct it found, such as a type alias or a typed parameter. Everything runs in your browser, so unreleased code and anything with a key in it never leaves your device.
The rest of the article, and all 6 questions about JavaScript Beautifier & Minifier, are on the JavaScript Beautifier & Minifier page.
Yes. No signup, no size limit and no cap on how many files you run through it. The page is paid for by a few ads shown outside the tool, and nothing is inserted into your code.
No. It reads plain JavaScript and JSX. If you paste TypeScript, the page tells you which construct it found, such as a type alias or a typed parameter, instead of showing a parse error that explains nothing. Strip the types first, or use a TypeScript-aware editor.
Readable source with comments usually drops 40 to 60 percent, and much more when it has long variable names and blank lines. Code that is already minified barely changes. The exact byte counts are shown, so you can compare.
You can get the layout back, not the names. Beautify adds line breaks, indentation and spacing so the code is readable, but a minifier discards the original variable names and comments, and no tool can recover them.
Still stuck? Ask about JavaScript Beautifier & Minifier and anybody who knows can answer. No account needed.
Same job, other tools: Unminify HTML – Expand minified HTML back into markup you can read and edit · Unminify CSS – Expand a minified stylesheet so you can read and edit the rules.
On the related tools: GraphQL Validator – Check a GraphQL query or schema for errors, optionally against your own SDL.
In the collection Code Formatters and Minifiers.