JSON Formatter & Validator
Paste messy JSON and get clean, indented, validated output instantly. Errors are pinpointed with line and column numbers. Your data stays in your browser — safe for API responses containing secrets.
Your JSON is processed entirely in your browser — it never leaves your device.
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How to use
- Paste your JSON into the input area.
- Click Format to beautify, or Minify to compress.
- Fix any highlighted errors, then copy the result.
Frequently asked questions
How do I find a JSON syntax error?
Paste the JSON and click Format — the validator reports the exact line and column of the first error, with a hint about what was expected.
Is it safe to paste API keys or tokens in JSON?
Yes. Unlike server-side formatters, ToolVeil parses JSON locally in your browser, so credentials in your data are never transmitted.
Can it handle large JSON files?
Yes — megabyte-sized JSON formats instantly. For extremely large files, use Minify to reduce size before sharing.