JSON formatter & validator
Pretty-print, minify and validate JSON. Paste JSON, get readable output or a clear error — all in your browser.
About this JSON formatter
Paste messy or minified JSON and get it pretty-printed with clean indentation, or minified down to a single line for transport. If the JSON is invalid, you get the exact parser error and position so you can fix it fast. It runs on the browser’s native JSON engine, so it’s instant and your data stays private.
Format vs minify
- Format (beautify) — adds 2- or 4-space indentation and line breaks so the structure is readable. Use it while debugging API responses or config files.
- Minify — strips all whitespace to produce the smallest valid JSON. Use it before embedding JSON in a request body or a data attribute.
How to use it
- Paste your JSON.
- Click Format (choose indent width) or Minify.
- Copy the result.
FAQ
Why does it say my JSON is invalid?
Common causes are trailing commas, single quotes instead of double quotes, unquoted keys, or comments — none are allowed in strict JSON. The error message points at the offending character.
Is my data sent anywhere?
No — parsing happens entirely in your browser using the native JSON engine.