JSON Formatter & Validator
Paste JSON below to format it with clean indentation, validate the syntax (with the exact position of the first error), or minify it back to a single line. Everything runs locally in your browser — safe for data you would not paste into random websites.
How to use it
- Paste your JSON.
- Click Format to pretty-print, or Minify to compress.
- Errors show the line and character where parsing failed.
Frequently asked questions
Why is my JSON invalid?
The most common causes: trailing commas after the last item, single quotes instead of double quotes, unquoted keys, and comments — none of which JSON allows.
Is it safe to paste sensitive JSON here?
The formatting happens entirely in your browser with JavaScript — the JSON is never uploaded. For highly sensitive data, you can verify by loading the page and going offline before pasting.
What indentation does the formatter use?
Two spaces by default, with a toggle for four spaces — the two most common conventions.
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