Programming Tools
Format, validate, and minify JSON in your browser. Your data stays on your device.
JSON workspace
On-device processing
Ready. Paste JSON or open a local file to begin.
Issues found
Showing up to 25 issues. Fix these to check for more.
Paste JSON or drop a UTF-8 file. Ctrl/Cmd + Enter formats it. Nothing is uploaded or saved. Large numbers are preserved exactly. Limit: 2 MB input, 128 nesting levels, and 10 MB formatted output.
How to format and validate JSON
- Paste your JSON or open a local JSON file.
- Syntax is checked automatically after you pause typing. Errors are marked beside the line numbers. Select an issue to jump to its line and column.
- Choose Format JSON for readable indentation or Minify for compact JSON, then copy or download the result.
What does validation check?
Validation checks JSON syntax: matching brackets, double-quoted keys and strings, commas, and valid values. Comments and trailing commas are not allowed. This tool does not validate against a JSON Schema or automatically change invalid data.
