JSON validator
Check whether your JSON is valid and pinpoint the first error precisely.
🔒 100% client-side — no data sent
Validate your JSON online and instantly pinpoint the syntax error: trailing comma, missing quotes, unclosed brace. Our JSON validator shows the exact line and column of the problem. Runs 100% in your browser, so your data never leaves your machine.
What is it for?
- ▸ Debug a REST API response that throws a parsing error.
- ▸ Check a config file (package.json, tsconfig) before deploying.
- ▸ Verify a payload before sending it in a POST request.
- ▸ Clean up JSON copied from logs to find the offending line.
FAQ
How do I find where the error is in my JSON?
The validator shows the line and column number of the first error, along with a message describing it (unexpected token, trailing comma, etc.).
Does JSON allow comments and trailing commas?
No. Strict JSON forbids comments and trailing commas after the last item in an object or array. These are common sources of errors.
Is my data sent to a server?
No. Validation runs entirely in your browser in JavaScript. No data is transmitted or stored.
What is the difference between validating and formatting JSON?
Validating checks that the syntax is correct; formatting (or beautifying) reorganizes already-valid JSON for readability. Validation is the prerequisite step.