Representative example
This example reflects the implemented transformation or analysis.
Input
function add(a,b){return a+b;}Output
function add(a, b) {
return a + b;
}JS Beautifier
Expand minified or cramped JavaScript into readable two-space-indented code with copying, samples, and `.js` download.
- Free public tool
- No sign-up for this tool
- Processing clearly labeled
- Instant results
Content last reviewed
67 characters · 1 lines
Structure comes back; names don't — variables minified to single letters keep their minified names. For debugging your own production code, source maps are the proper fix.
Quick Start
Add input
Paste JavaScript and review the automatically beautified result.
Choose options
Sample loading, resizable split view, copy, and download.
Review the result
Check the output or diagnostics, then use the available copy or download control where shown.
Examples
Input and output example 1
Input
function add(a,b){return a+b;}Output
function add(a, b) {
return a + b;
}About the JS Beautifier
JS Beautifier addresses a focused developer workflow without requiring a command-line setup. Expand minified or cramped JavaScript into readable two-space-indented code with copying, samples, and .js download. Results update from the supplied input, making it useful for quick inspection, debugging, documentation, or test preparation.
In this tool, JS Beautifier: processing runs in the browser and the tool does not call an external conversion API. Input remains in page memory unless a confirmed browser feature such as file reading or local settings is described above.
How to Use JS Beautifier
Paste JavaScript and review the automatically beautified result.
Configure sample loading, resizable split view, copy, and download.
Review the generated output, status, or validation message.
Copy or download the result when that control is available, and verify it in the destination where it will be used.
Key Features
Focused processing
The bundled
js-beautifyJavaScript formatter rewrites layout with an indent size of two spaces.Input guidance
JavaScript source text.
Immediate feedback
A formatter error is shown when the library cannot process the supplied text.
When to Use JS Beautifier
Application development
Use JS Beautifier to prepare or inspect values while implementing a feature.
Fault isolation
Run a small known input through JS Beautifier to distinguish formatting or syntax problems from surrounding application behavior.
Reviewable examples
Create a concise function add(a, b) { for tests, documentation, or code review.
How It Works
Processing flow
The bundled js-beautify JavaScript formatter rewrites layout with an indent size of two spaces.
Result handling
During processing, JS Beautifier: the result is rendered directly in the tool interface. Validation failures are displayed instead of being silently treated as successful output.
Supported Formats and Options
Formats
Accepted input
JavaScript source text
Displayed output
function add(a, b) {
Options
Available controls
Sample loading, resizable split view, copy, and download
Common Errors and Troubleshooting
Common errors
Invalid or incomplete input
A formatter error is shown when the library cannot process the supplied text.
Unexpected result
Confirm that the selected mode or syntax matches the source and that the input is complete.
Troubleshooting guide
Resolve the reported error
A formatter error is shown when the library cannot process the supplied text. Reduce the input to the smallest failing case and confirm the selected controls.
Check an unexpected result
Review the documented limitation for JS Beautifier, then compare a known example with the same mode or syntax before processing a larger value.
Limitations and Important Notes
Beautifying changes layout, not semantics or minified variable names. It does not replace source maps, linting, parsing, or deobfuscation.
Privacy and Data Processing
JS Beautifier performs its implemented transformation in the browser without calling an external processing API. Input is held in the current page state, so still avoid unnecessary secrets and clear the field on a shared device.
Tips and Best Practices
Practical tips
Keep the original javascript source text before using JS Beautifier.
Exercise the error case described as: A formatter error is shown when the library cannot process the supplied text.
Check the result against this limitation: Beautifying changes layout, not semantics or minified variable names. It does not replace source maps, linting, parsing, or deobfuscation.
Best practices
Prepare a representative input
Start with a small value whose expected result you understand, then add the edge cases relevant to JS Beautifier. Preserve the original when the conversion or formatting is destructive.
Verify in context
Beautifying changes layout, not semantics or minified variable names. It does not replace source maps, linting, parsing, or deobfuscation. Treat the displayed result as an intermediate artifact and test it in the runtime, parser, database, or document where it will actually be used.
Technical Details
The bundled js-beautify JavaScript formatter rewrites layout with an indent size of two spaces.
Who Is This For?
Developers, QA engineers, technical writers, analysts, and students who need expand minified or cramped JavaScript into readable two-space-indented code with copying, samples, and .js download.
Frequently Asked Questions
Does JS Beautifier send input to an API?
No external processing API is used by this tool; its implemented operation runs in the browser.
What input is supported?
JavaScript source text.
Why did the tool show an error?
A formatter error is shown when the library cannot process the supplied text.
What should I verify before using the result?
Beautifying changes layout, not semantics or minified variable names. It does not replace source maps, linting, parsing, or deobfuscation.