JSON Formatter & Validator
Free online JSON formatter and validator. Beautify, minify and check JSON syntax instantly in your browser — nothing is uploaded, no sign-up needed.
Configuration Panel
About JSON Formatter
Our JSON Formatter is a free, client-side tool that helps you format, validate, and minify JSON data instantly. No uploads, no server processing—everything happens in your browser for maximum speed and privacy.
Features
- Format and beautify JSON with proper indentation
- Validate JSON syntax instantly
- Minify JSON to reduce file size
- 100% client-side processing
How to Use
- Paste or type your JSON in the input box
- Click "Format" to beautify or "Minify" to compress
- Click "Validate" to check for syntax errors
- Copy the result with one click
Frequently Asked Questions
Does this tool upload my JSON data?
No. All processing happens locally in your browser. Your JSON data never leaves your device.
Is there a file size limit?
There is no fixed limit. Because formatting happens in your browser, JSON documents of several megabytes work fine; very large files are limited only by your device's memory.
Does the validator check for trailing commas?
Yes, our JSON validator strictly follows standard JSON syntax rules, which means trailing commas will be flagged as syntax errors.
Can I format minified JSON back to readable format?
Absolutely. You can paste any valid minified JSON into the input box and click 'Format / Beautify' to instantly restore proper indentation.