JSON Validator — Check If Your JSON Is Valid Instantly

Paste any JSON to validate its syntax against the RFC 8259 standard. Get detailed error messages with line numbers and auto-fix for common mistakes.

Common JSON Errors

JSON is strict. Unlike JavaScript objects, JSON requires double quotes around all keys and string values, no trailing commas after the last item in arrays or objects, and no comments of any kind. These rules trip up developers daily.

Our auto-fix feature can repair most of these errors automatically. Click “Try to Fix” and the tool will replace single quotes, remove trailing commas, quote unquoted keys, and strip comments.

Why Validation Matters

Malformed JSON breaks API calls, crashes parsers, and causes silent data loss. A missing comma or extra bracket can take hours to debug in a large file. This validator pinpoints the exact error location so you can fix it in seconds.

Paste your JSON below to validate it instantly.

Formatted output will appear here...

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