JSON Validator

"Invalid JSON" is a useless error message when you're staring at a 2,000-line API response. Paste your JSON above and this validator tells you exactly where it breaks — the position of the missing comma, the unclosed bracket, the smart quote that snuck in from a Word document — so you fix the actual problem instead of re-reading the whole payload.

Everything is checked locally in your browser, so production payloads and API responses with real data stay on your machine.

FAQ

Does JSON allow trailing commas?

No — trailing commas are the most common reason real-world JSON fails validation. They're legal in JavaScript and JSON5, but not in strict JSON.

Can JSON contain comments?

No. Standard JSON has no comment syntax. If your file has // or /* */ comments, it's JSONC/JSON5, not JSON — strip them before validating.

What's the difference between validating and formatting?

Validating only tells you whether the JSON parses and where it fails. If you want it pretty-printed too, use the JSON Formatter.