JSON Validator
Check whether JSON is valid and see exactly what broke.
Private by design. This tool runs entirely in your browser. Your input is processed on your own device and is not uploaded by DO101.
About the JSON Validator
A focused pass/fail check for JSON. Valid documents report their type, key count and nesting depth. Invalid documents get the line, column and the offending snippet highlighted.
How to use it
- 1Paste the JSON you want to check.
- 2Read the pass or fail banner.
- 3Jump to the reported line to fix an error.
What you get
- Instant valid / invalid verdict
- Line and column of the first error
- Key count, depth and root type
- Duplicate key warning
- No upload
Frequently asked questions
Does it validate against a JSON Schema?
Not yet. This tool checks syntax — whether the document is parseable JSON. Schema validation is on the roadmap.
Are duplicate keys invalid?
Strictly they are allowed by the spec, but almost every parser silently keeps only the last one, so DO101 warns you when it spots them.
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