JSON Formatter
Format, validate, and minify JSON online. Syntax highlighting, error detection, indent control. Free and instant.
Runs in your browser
No account needed
Completely free
Indent:
Input JSON
Output
Output will appear here…
About JSON Formatter
Format messy JSON into clean, readable output with proper indentation. Validate syntax and see exactly where errors occur. The minify mode removes all whitespace for the smallest possible output size. All processing happens instantly in your browser — no data is sent to any server.
Frequently asked questions about JSON Formatter
Yes. Invalid JSON shows a clear error message indicating exactly what went wrong and where.
Yes. Switch to Minify mode to remove all whitespace and produce the most compact JSON output.
Since processing happens in your browser, the limit is your device memory. JSON up to several MB works fine.
Each line must be independently valid JSON. The formatter processes single JSON objects or arrays, not multi-line JSONL files.