JSON Validator
Validate JSON and get a summary of its top-level keys and types.
Free No signup Runs in your browser — nothing uploaded
Result
What it does
JSON Validator reads the whole document before doing anything, so what comes back is either valid output or a specific error with the position that caused it — not a partially rewritten file.
When you need it
Usually when something has already gone wrong: a config file an application will not load, an API response that has to be read by a human, or an export that has to be checked before it goes anywhere near a database.
Limits and caveats
Key order is preserved as it appears in the input. Very large documents are limited by your device's memory rather than by an upload cap, since the parsing happens locally. Everything happens in your browser, so the file never leaves your device.
How to use the JSON Validator
- Paste your content, or load a file.
- The result appears as you type.
- Copy or download the output.
Frequently asked questions
- Does it check against a schema?
- Not yet — this validates syntax and describes the shape.
- Do my files get uploaded?
- No. This tool runs entirely in your browser, so the file never leaves your device.