JSON Validator
Paste JSON to check whether it is valid. Errors are pinpointed with the line, column and a caret under the problem, and valid JSON gets a quick summary of its structure.
Runs in your browser
How to use
- Paste the JSON.
- Read the result: valid, or the exact error location.
- Fix the highlighted spot and re-check instantly.
How it works
Validation uses the strict JSON grammar (RFC 8259). Common mistakes it catches: single quotes instead of double quotes, trailing commas, unquoted keys, comments, NaN or Infinity values and missing brackets.
The structure summary counts keys across all objects and measures maximum nesting depth, which helps spot unexpectedly deep or large payloads.
Examples
- Trailing comma
- {"a": 1,} → error at line 1, column 9: a property name was expected after the comma.
Common uses
- Debugging API payloads
- Checking configuration files before deploying
- Validating data exported from other tools
Privacy & security
This tool runs entirely in your browser. Your files and text are never uploaded to our servers — processing happens on your device and results are created locally. How each tool handles files
Frequently asked questions
Does it validate against a JSON Schema?
No. It checks syntax only. Schema validation (types, required fields) is a different step.
Why is my JavaScript object rejected?
JavaScript object literals allow single quotes, unquoted keys and trailing commas. JSON does not.
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