JSON Formatter & Validator

Format, validate, minify and syntax-highlight JSON — detect errors instantly

Input JSON
Formatted Output
Size —
Lines —
Keys —
Status —

About This Tool

The free JSON Formatter and Validator instantly beautifies messy JSON, validates its structure, minifies it for production, and renders it with syntax highlighting. Uses the native browser JSON parser for error detection at exact positions. No data ever leaves your browser.

Common Use Cases

Frequently Asked Questions

JSON formatting (beautifying) adds consistent indentation and line breaks to compact JSON, making it human-readable.
Yes. The tool uses the browser native JSON.parse() and highlights any syntax errors with a descriptive message.
No. All processing happens entirely in your browser. Your data never leaves your device.
Formatting adds whitespace for readability. Minifying removes all unnecessary whitespace to reduce file size.