{ } JSON Formatter & Validator
Paste or open any JSON — get it pretty-printed or minified, with validation errors pinpointed to the exact line and column.
valid JSON ✓
How the json formatter & validator works
The input is parsed with the browser’s native JSON parser — the same engine your applications use — so validation verdicts match reality exactly. Errors are reported with the line and column of the first problem. Formatting re-serializes with your chosen indentation; minifying strips all insignificant whitespace (typically 20–40% smaller for config-style JSON).
The classic use is debugging: an API response or config file that "should work" gets pasted here, and the line/column error message finds the trailing comma or unquoted key in seconds. JSON is often confidential — payloads, configs, credentials — which is why this formatter never transmits a byte.
Frequently asked questions
Why is my JSON invalid?
The usual suspects: trailing commas (allowed in JavaScript, forbidden in JSON), single quotes instead of double, unquoted keys, and comments (JSON has none). The error message points at the first offending line and column.
Does minifying change my data?
No — only whitespace between tokens is removed. Values, key order and structure are byte-identical when parsed.
Is there a file-size limit?
No hard limit — parsing is local, so multi-megabyte files work without upload caps or paid tiers.
Can I validate without reformatting?
Yes — the verdict ("valid JSON ✓" or the error) appears regardless; just ignore the output pane if you only needed validation.
Is my JSON kept private?
Completely — parsing runs in your browser and the page works offline. API payloads and configs never touch a server here.
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