JavaScript Beautifier reformats minified or compressed JavaScript into properly indented, multi-line code so you can read, audit, and debug what is actually running in production.
JavaScript Beautifier is a free, browser-based tool that takes any JavaScript — whether it arrives as a production-minified bundle, a pasted snippet from a developer tools tab, or a quick test from a console — and rewrites it with one statement per line, indented braces, and spacing that matches what most modern style guides expect. The result is code that reads like a human-authored module instead of a single dense line.
JavaScript Beautifier is token-aware: string literals, template literals, regular expressions, and comments are preserved verbatim while only the whitespace between tokens is adjusted. That means the reformatted output behaves identically to the original, even when the source contains tricky cases like regex literals after a return statement or template literals with embedded expressions.
Typical users are developers reverse-engineering a minified script during a bug investigation, security engineers reading a third-party tag for compliance, frontend authors auditing what a build pipeline produced, and educators teaching the structure of JavaScript by showing a clean version of compiled output. Because the tool runs locally, your proprietary scripts and customer-facing JS never leave the device during formatting.
JavaScript Beautifier classifies every part of the source as a string, regex, template literal, comment, keyword, or operator before reformatting. That eliminates the regex pitfalls that break naive beautifiers when a slash appears inside a regular expression or template literal.
Strings, template literals (including embedded expressions), and regex literals are emitted byte-for-byte. The tool never alters a value, only the whitespace around it.
Binary operators receive predictable spacing on either side, which matches Prettier and most popular style guides. The result is a stable, diffable, review-friendly representation of the code.
Semicolons break lines at the top level so each statement appears on its own line. Inside parenthesised expressions the tool keeps the structure together to avoid creating false statement boundaries.
Choose 0 to 8 spaces of indent. Most modern teams use 2; older codebases sometimes use 4. The option keeps the output aligned with whatever EditorConfig or Prettier already enforces.
All beautification happens in your browser, which keeps proprietary scripts, internal bundles, and confidential code snippets confidential during formatting.
JavaScript has a few syntactic edge cases that defeat naive beautifiers. The most famous is the regex versus division ambiguity: a single forward slash can start a regex literal or denote division, depending on the preceding token. JavaScript Beautifier resolves this by tracking what came before — after a keyword like return, throw, or typeof, a slash starts a regex; after a closing parenthesis or identifier, it is a division operator.
Template literals introduce a second class of difficulty. A backtick opens a string that can contain newlines, escape sequences, and embedded expressions delimited by ${ … }. The tool walks template literals manually so that braces inside an expression do not accidentally close the enclosing function body.
Comments are the third edge case. Line comments end at the next newline; block comments end at the next */. Re-emitting them in the wrong place can change adjacent semantics — for example, a block comment between a label and a colon can break parsing. JavaScript Beautifier keeps comments anchored to the statement they came with so the output remains correct.
Input
function add(a,b){return a+b}const x=add(1,2);Output
function add(a, b) {
return a + b
}
const x = add(1, 2);Minified production bundles are unreadable in their original form. Beautifying first turns them into something you can scan during a bug investigation or security review.
JavaScript Beautifier is great for inspecting unfamiliar code, but for files you actively maintain, use Prettier or your editor formatter. Those tools understand more idioms and produce output you can commit confidently.
When the source has been obfuscated (renamed variables, string-array encoding), beautify first and then run the result through DeObfuscator for a more readable view of the logic.
Beautifier output is for human readers, not for production traffic. Once you are done reading or editing, run the result through Minifier so visitors still receive the smallest possible payload.
When two bundles differ only in whitespace, beautifying both first turns the diff into a meaningful comparison of logic changes rather than line-break noise.
That is intentional. Regex literals are preserved verbatim — the beautifier never inserts whitespace inside them.
Paste at least one character of code into the input textarea, then click Beautify again.
Webpack, Vite, and esbuild all minify by default. JavaScript Beautifier reverses that compression so you can read and debug what is actually running in production.
Source maps are not always available. Beautifying the relevant bundle gives you enough context to understand the surrounding logic and reproduce a bug locally.
Security and privacy reviews of vendor scripts need a readable view of the code. Beautifying produces a clean version that is much easier to audit line by line.
Code copied from Slack, GitHub Issues, or PDF tutorials often loses formatting. Beautifying restores readable indentation so the snippet can be evaluated quickly.
When a dependency upgrade changes the minified bundle, the diff is overwhelming. Beautifying both versions turns it into a manageable comparison of behaviour.
No. The tool only changes whitespace between tokens. Strings, regex, template literals, and comments are preserved exactly, so the beautified code behaves identically to the original in every JavaScript engine.
Yes. The tokenizer recognises template literals (including embedded expressions) and regex literals, and treats them as atomic values that should not be reformatted internally.
By looking at the previous significant token. After keywords like return, throw, typeof, or an opening bracket, a slash starts a regex. After an identifier, number, or closing parenthesis, the same slash means division. This is the same rule the JavaScript spec uses.
It is ready for reading and review. For production deployment, run the beautified output through JavaScript Minifier so users still get the smallest possible payload.
No. The tool only reformats whitespace and never validates the source. If the input has a syntax error, the output will too. Use your editor or a real parser like Acorn to validate before beautifying.
No. All processing happens in your browser. Your scripts are never uploaded, so proprietary code and internal bundles remain confidential during formatting.
Yes, by running the output through JavaScript Minifier on the same site. Round-tripping through both tools is safe as long as the input is valid JavaScript.
Prefer Prettier for source files you maintain in a repo — it understands more idioms and produces output you can commit. Use JavaScript Beautifier when you only need to read or audit unfamiliar minified code, especially when installing Prettier locally is not an option.
JavaScript Beautifier turns minified bundles back into readable code in one click — privately, in your browser, with no signup required.