Developer Tools
JSON Validator
Paste JSON to instantly check if it is valid. Get precise error messages to fix issues fast — free, browser-based.
No uploads — browser onlyInstant result
JSON Input
How to validate JSON
- Paste your JSON into the input area.
- Click Validate JSON — you'll see a green tick or a red error with the exact location of the problem.
- Copy the result to your clipboard with one click.
Privacy — your data stays local
Everything runs in your browser with the native JavaScript JSON API. No data is ever sent to a server.
Frequently Asked Questions
What causes a JSON validation error?
Common causes include trailing commas, single quotes instead of double quotes, unquoted keys, and missing closing brackets or braces.
Does this tool validate JSON Schema?
No — it validates JSON syntax only. If you need JSON Schema validation, you'll need a dedicated tool.
Can I validate large JSON files?
Yes — paste as much JSON as you like. The only limit is your browser's memory.
Is this a strict JSON parser?
Yes, it uses the browser's native JSON.parse(), which is fully RFC 8259 compliant.