JSON Validator
Check whether a document parses, and see exactly where it fails.
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About this tool
Reports the line and column of the first syntax error along with a snippet of the surrounding text, rather than a bare invalid flag.
Limitations
- This checks syntax, not shape. To assert that fields exist and have the right types, use the JSON Schema Validator.
Questions
- My JSON looks fine but it says invalid.
- The usual culprits are a trailing comma after the last element, single quotes instead of double, unquoted keys, or a comment. All four are valid JavaScript and none are valid JSON.
- Can it check the shape, not just the syntax?
- Not here — this only checks whether the document parses. Use the JSON Schema Validator to assert required fields, types and constraints.
- What about JSON5 or JSONC?
- Those are different formats that permit comments and trailing commas. This validator applies strict JSON rules, so it will reject them.
Privacy
This page does its work in your browser. What you paste is processed by JavaScript running on your own device and is never sent to a DevToolery server — there is no server that could receive it. The page itself is a static file delivered by a CDN. See exactly what is stored.