JSON Formatter & Validator

Paste JSON, get clean readable output — or a precise error telling you exactly what went wrong and where.

About this tool

JSON is the default data format of modern APIs, but it usually arrives as a single long line that is impossible to read. This tool re-indents your JSON into a readable tree, validates it against the JSON specification, and minifies it back into a compact form for transport or storage.

How to use it

  1. Paste your JSON into the input box (or click Sample to try it first).
  2. Click Format / Beautify to pretty-print, or Validate to only check it.
  3. If something is wrong, the error message shows the exact line and column — fix it and format again.
  4. Use Copy to take the result back to your editor.

Good to know

  • The validator reports the position of the first syntax error, including line and column numbers.
  • Turn on Sort keys alphabetically to normalise object keys — handy for comparing two payloads.
  • Minify removes all unnecessary whitespace, which is what you usually want when storing or sending JSON.
  • Duplicate object keys are allowed by the parser (the last value wins) — this matches how most browsers behave.