JSON Formatter / Validator
Paste JSON and get instant formatting with line-accurate error reports
Quick guide
What can JSON Formatter help you do?
Free online JSON formatter, minifier, and validator. Error line-number locator, tree view, one-click copy. Runs in browser — your JSON never uploaded.
Best for
Useful for quick file work, text cleanup, calculations, content creation, and website or AI checks.
How to use it
Open the tool, enter or upload what it asks for, then copy or download the result directly.
Privacy and limits
Most tools run in your browser with no sign-in. Very large files or older devices may hit browser memory limits.
Frequently Asked Questions
How do I find a JSON syntax error?
This tool reports the exact line and position, like "Unexpected token at line 5, position 12", and highlights the line.
Can I minify JSON?
Yes — the "Minify" button compresses multi-line JSON to one line for API payloads or database storage.
Is there a one-click copy?
Yes — the copy button at the top-right of the output box copies the formatted JSON to your clipboard.
Does this tool store my JSON?
No. All processing happens in your browser. Your JSON is never uploaded — safe for sensitive data.
What's the max JSON size?
Theoretically unlimited (browser memory permitting). 10 MB or less is fast in testing.