JSONLint is the fastest way to find out why your JSON will not parse. Paste it in, and instead of a vague error from your application you get the specific line and character where the syntax breaks.
JSON syntax errors are notoriously annoying because the failure message from a parser is often useless — "unexpected token" without telling you where. JSONLint points at the exact position and usually describes what it expected instead.
It catches the mistakes that actually happen in practice: trailing commas after the last array element, single quotes instead of double, unescaped characters inside strings, comments (which JSON does not permit), and mismatched brackets.
Once valid, you can pretty-print with proper indentation or minify to a single line for shipping. It runs in the browser with no registration.
| Registration | Not required |
|---|---|
| Watermark | None |
| Cost | Free |
| Functions | Validate, format/pretty-print, minify |
| Error reporting | Exact line and position with description |
| Input | Paste, upload or load from URL |
| Processing | Browser-side |
Check before you rely on it: free quotas, file limits and pricing change frequently. Confirm current terms on the official site before depending on it for regular work.
Developers debugging API responses, anyone hand-writing config files, and students learning JSON syntax. If a JSON file refuses to load, this is the first place to paste it.
Yes, validation and formatting are free with no registration required.
Yes — it reports the line and position of the syntax error along with a description of what it expected.
Trailing commas, single quotes, unescaped characters, comments, mismatched brackets and other invalid syntax.
Yes, it can both pretty-print with indentation and minify to a single line.
No, it checks syntax only. Schema validation needs a different tool.
Validation runs in the browser, but avoid pasting sensitive credentials into any online tool as a habit.