Format and validate JSON
Pretty-print, minify and validate JSON with precise error messages.
Runs on your device — never uploaded
How to format and validate JSON
- Paste JSON
From an API response, config file or log.
- Format or minify
Choose 2 or 4 spaces, tabs, or minified output. Keys can be sorted.
- Fix errors
Invalid JSON shows the line and column of the problem.
Frequently asked questions
Is my JSON uploaded?
No. Parsing uses your browser's built-in JSON engine; there is no network request. Safe for tokens and secrets.
Can it handle large files?
Yes, multi-megabyte documents format in well under a second.
Does it support comments or trailing commas?
Strict JSON does not, and the validator flags them. Use the relaxed option to strip comments and trailing commas first.