Browser tool Runs locally
JavaScript Formatter & Beautifier
Format JavaScript with a real ECMAScript parser. Supports modern syntax, preserves comments and strings, and never executes your code.
JavaScript input
0 chars⌘/Ctrl + Enter to format
Formatted JavaScript
Formatted JavaScript will appear here.Examples:
How to format JavaScript
- Paste JavaScript in the input panel.
- Choose the indentation.
- Click Format JavaScript.
- Copy or download.
What this JavaScript formatter supports
- Standard ECMAScript through ES2024.
- Arrow functions, async/await, generators.
- Classes with private fields and static blocks.
- Modules, dynamic import, import.meta.
- Optional chaining, nullish coalescing, logical assignment.
- Template literals and regular expressions.
Supported syntax and limitations
- Supported: standard JavaScript.
- Not supported: JSX, TypeScript, Flow, Vue SFCs, Svelte, CoffeeScript.
- Unsupported input produces a clear message instead of partial output.
Formatting is not validation or linting
The formatter must parse the input before it can print it, and it reparses the generated output to catch formatter errors. That checks syntax, but it does not perform style linting or prove that the program behaves as intended.
Comments, strings, and ASI
Comments are parsed separately from program tokens and preserved in the formatted output. String literals and template literals are treated as syntax rather than raw whitespace, so their contents are not reformatted. The printer emits statement terminators explicitly, which matters for JavaScript programs that otherwise rely on automatic semicolon insertion.
Frequently asked questions
- Does this JavaScript formatter upload my code?
- No. Parsing and formatting run entirely in your browser.
- Does it execute my JavaScript?
- No. The parser reads source as text; nothing is evaluated.
- What JavaScript syntax does it support?
- Standard ECMAScript through ES2024.
- Does it support JSX or TypeScript?
- No. Non-standard syntax is reported clearly.