ZeroData Tools
Tools
JSON to CSV Custom Map nested JSON arrays into clean CSV files by visually selecting the exact columns you want. JSON Formatter Format and validate JSON instantly with no uploads, no server calls, and no stored data. JSON Validator Validate JSON instantly before deploys with local processing and zero server calls. YAML Validator Validate YAML files and catch indentation errors instantly with no uploads or backend processing. Base64 Encoder Encode or decode Base64 strings instantly with zero uploads. URL Encoder Encode and decode query parameters locally for APIs, redirects, and forms. HTML Formatter Pretty-print messy markup and inspect structure without exposing page code. CSS Minifier Shrink stylesheets for production with browser-only processing and instant output.

JavaScript Beautifier

Reformat dense JavaScript into readable code locally for debugging.

Ready to use Runs locally in your browser
How this tool works

Reformat dense JavaScript into readable code locally for debugging.

  1. Paste JavaScript into the input editor.
  2. Use Beautify to reformat the code with normalized spacing and indentation.
  3. Use Validate to check that the code parses cleanly.
  4. Copy or download the result once the output looks right.
Input example 
{config.exampleBefore}
Output example 
{config.exampleAfter}
JavaScript Beautifier
Processed entirely in your browser. No uploads, no background processing, and no account required.
Ctrl+Enter Beautify Ctrl+Shift+Enter Validate Ctrl+Shift+C Copy
JavaScript input Editable input
1 line | 0 chars | 0.0 KB
Beautified JavaScript Read only output
1 line | 0 chars | 0.0 KB
Ready Browser only
Paste content into the input editor and run an action.

This tool runs 100% in your browser; your data never leaves your device. Privacy details

How to Use the JavaScript Beautifier

  1. Paste JavaScript into the input editor.
  2. Use Beautify to reformat the code with normalized spacing and indentation.
  3. Use Validate to check that the code parses cleanly.
  4. Copy or download the result once the output looks right.

Common Use Cases

  • De-minifying production JavaScript code to debug a console error occurring only on the live website.
  • Formatting an inherited, messy legacy JavaScript file to make it readable before beginning a refactor.
  • Auditing a third-party tracking script or widget for privacy concerns or malicious activity.
  • Standardizing the code style of a script before submitting it for a team code review.
  • Extracting and understanding the logic of a complex JSON object or configuration embedded in a JS file.

Frequently Asked Questions

Will beautifying my JavaScript change how it executes?

No, beautifying only alters the whitespace, indentation, and formatting of the code. The underlying logic, variable names, and execution order remain completely unchanged.

Can this tool decode heavily obfuscated JavaScript?

The beautifier will correctly indent and format obfuscated code, making the structure visible. However, it will not rename mangled variables (e.g., changing 'a' back to 'userData') or decrypt encoded strings.

Does the beautifier support modern ES6+ syntax?

Yes, it fully supports modern ECMAScript features including arrow functions, classes, async/await, and template literals.

Can I use this tool to format JSON files?

Yes, because JSON is a subset of JavaScript object syntax, the beautifier will perfectly format raw or minified JSON strings into a readable structure.

Is it safe to paste code containing API keys into this tool?

Yes. The tool processes everything locally in your browser. Your code, including any sensitive keys or tokens, is never sent over the network to any server.

Explore more ZeroData utilities

Related Tools

HTML Formatter

Pretty-print messy markup and inspect structure without exposing page code.

CSS Minifier

Shrink stylesheets for production with browser-only processing and instant output.

Regex Tester

Test regex patterns instantly in-browser with no uploads, no logging, and immediate match feedback.

JSON to TypeScript

Generate TypeScript interfaces from JSON API responses locally and securely.