JSON Validator
Validate JSON syntax and identify exactly where errors are.
About JSON Validator
JSON Validator parses a document and reports the first syntax error with its line and column, which is usually faster than reading a stack trace from an application.
It checks structure, not schema: valid JSON can still be the wrong shape for your API. Use it to separate syntax problems from contract problems.
How to use JSON Validator
- 1
Paste the JSON
Parsing runs in the browser; tokens and secrets stay local.
- 2
Read the error
The line and column point at the first failure, not every failure.
- 3
Fix and revalidate
Trailing commas and unquoted keys are the most common causes.
Questions about JSON Validator
Why is a trailing comma invalid?
Strict JSON forbids it, unlike JavaScript object literals. Remove the last comma in every array or object.
Are comments allowed?
No. JSON has no comment syntax; a // line is a syntax error.
Does it validate against a schema?
No, syntax only. Schema validation needs a JSON Schema validator.
Is my JSON uploaded?
No, validation is local to the browser.
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Last updated November 2026. Files are processed on FilePlume's own hardware and deleted within 60 minutes; nothing is used for training.