JSON Formatter & Validator

Beautify, validate and minify JSON with clear error locations.

100% client-side Instant results Free forever Nothing uploaded

About the JSON Formatter & Validator

Paste JSON to pretty-print it with your chosen indentation, validate it with precise error messages (including line/position of the first error), or minify it for production. Processing is local — safe for API keys and private payloads.

Malformed JSON is the most common API debugging problem; the exact error location saves minutes every time.

How to use the JSON Formatter & Validator

  1. Paste your JSON into the editor.
  2. Click "Format" to beautify, or "Minify" to compress.
  3. If invalid, the error message pinpoints the problem position.

Common uses

Debugging API responses Cleaning config files Minifying JSON for production payloads

Frequently asked questions

Is my JSON sent to a server?
No — parsing and formatting run entirely in your browser, so pasting sensitive payloads is safe.
What are the most common JSON errors?
Trailing commas, single quotes instead of double, and unquoted keys. The validator identifies where parsing failed.
Can it handle large files?
Multi-megabyte JSON formats in well under a second on a modern device.

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