How do I use the JavaScript Formatter & Validator?

Format, validate, and minify JavaScript code online. Detects syntax errors instantly with clear error messages — all processed locally in your browser for speed and privacy. Simply enter your values and click calculate to get instant results.

Is the JavaScript Formatter & Validator free?

Yes, all calculators on AllCalculators.org are completely free to use with no registration required.

JavaScript Formatter & Validator

Paste JavaScript to format, validate, or minify — processed locally in your browser

Indentation

Input JavaScript

Ctrl+Enter to process

Output

About This Tool

Format — Reformats JavaScript with consistent indentation and line breaks for readability.
Minify — Strips comments and unnecessary whitespace to reduce file size.
Validate — Checks for syntax errors and reports the exact error location with code stats.
Local Processing — Your code never leaves the browser. Everything runs on your device.
Large Files — Efficiently handles JavaScript files up to several megabytes.