JavaScript Beautifier & Formatter Online
Instantly format, unminify, and clean messy or compressed JavaScript (.js / .min.js) in real time. Our token-aware JS formatter accurately handles ES6+ arrow functions, template literals, regular expressions, for loops, https:// URLs, and chained method calls—and includes a one-click JS Minifier for compact production code.
How to Beautify & Unminify JavaScript Online
- Paste Your Code: Paste your compressed
.min.jsbundle or unformatted script into the Input JavaScript editor on the left, or click Load Sample to test ES6+ features. - Pick a Quick Preset or Customize Options: Click 2 Spaces (Standard), 4 Spaces, Allman + Chain Break, or Minify (.min.js), or fine-tune brace placement, conditional spacing, and comment removal in the right-hand panel.
- Review in Real Time: The formatted output and character/line/block counters update automatically as you type or toggle settings.
- Copy or Download: Click Copy to Clipboard or Download .js to save
script.beautified.js(orscript.min.js).
JavaScript Formatting Options Explained
| Option | What It Controls | Before | After |
|---|---|---|---|
| Same-Line Braces (K&R) | Places opening { on the header line (checked) or on a new line in Allman style (unchecked). |
if(ok){run();}else{stop();} |
if (ok) { |
| Space Before Conditional | Controls whether a space appears between if, for, while, switch, catch and (. |
for(let i=0;i<5;i++) |
for (let i = 0; i < 5; i++) |
| Break Chained Methods | Splits fluent method chains (.filter().map().sort()) across indented lines. |
items.filter(fn).map(fn).sort(); |
items.filter(fn) |
| Remove Comments | Strips // and /* */ comments while keeping https:// strings and regexes untouched. |
const u = "https://a.com"; // url |
const u = "https://a.com"; |
Why Use a Token-Aware JavaScript Formatter?
Formatting JavaScript with simple text-replacement rules often breaks valid code because characters like /, ;, and { mean different things depending on context. Our formatter uses a dedicated JavaScript lexical tokenizer that understands:
- Strings & ES6 Template Literals: Single quotes (
'...'), double quotes ("..."), backtick template strings (`Hello ${name}`), and escaped backslashes ("C:\\Users\\") are preserved verbatim. - Regular Expressions vs. Division: Distinguishes regex literals like
/^user_[0-9]+;?/ifrom division expressions like(a + b) / 2so semicolons or slashes inside a regex never split the line. for (...)Loop Headers: Semicolons insidefor (let i = 0; i < n; i++)stay on the same header line instead of breaking into three separate lines.- Safe Comment Stripping: Single-line
//and multi-line/* */comments are tokenized separately, so URLs like"https://api.example.com"are never truncated when removing comments.
Frequently Asked Questions
How do I unminify a .min.js file online?
Paste your compressed .min.js code into the Input JavaScript editor on the left. The tokenizer automatically expands statements, blocks, functions, and loops with clean multi-line indentation in real time.
Does removing comments affect https:// URLs or regex literals in my JavaScript?
No. Because our formatter uses a lexical tokenizer rather than a naive regular expression, // and /* */ inside single-quoted strings, double-quoted strings, template literals, and regular expressions (/pattern/g) are never stripped or modified.
What is the difference between K&R (same-line) and Allman (new-line) brace style?
K&R style places the opening curly brace { on the same line as the function, if, or loop header (the standard in most JavaScript style guides). Unchecking Same-line braces switches to Allman style, placing the opening brace on its own new line aligned with the closing brace.
Can I also minify JavaScript with this tool?
Yes. Click the Minify JS button (or select Minify (Single-Line .min.js) in the settings panel) to strip comments and unnecessary whitespace while keeping required keyword spaces intact.
Is my JavaScript code uploaded to any server?
No. All JavaScript formatting and minification executes 100% locally in your browser. Your source code never leaves your device.