Format, validate, and beautify JSON data with syntax highlighting.
A free, in-browser JSON formatter, validator, and beautifier. Paste any JSON blob and instantly get cleanly indented, syntax-highlighted output — or catch invalid JSON with a clear error message. All processing happens locally in your browser, so your data never leaves your device.
Paste your JSON
Paste raw JSON into the input area. Minified, multi-line, or pretty-printed all work.
Format or validate
Click Format to beautify with two-space indentation and syntax highlighting. If the JSON is invalid, you'll see the exact position of the error.
Copy or download
Copy the formatted output with one click, or download it as a .json file.
No. All parsing and formatting happens locally in your browser using JavaScript. Nothing is uploaded.
There's no hard limit — it depends on your browser's memory. Files up to several megabytes typically work without issue.
Yes. The formatter can produce both pretty-printed and minified (single-line) output.
No. This tool validates that the JSON is syntactically correct. For schema validation (JSON Schema), you'll need a dedicated validator.