JSON Validator
Check whether your JSON is valid and see exactly where it breaks, with the line and column. Runs in your browser.
Find the broken comma fast
Paste any JSON and this validator tells you right away whether it parses, using the same strict engine your browser ships. When it fails, you get the real error message plus the line and column where the parser gave up, so you can jump straight to the stray comma, the missing quote, or the trailing bracket. When it passes, you also get a quick count of object keys and array items so you know roughly what you are holding. Nothing is uploaded; your payload stays on your machine.
For the config blobs you paste all day
API responses, environment configs, that webhook body you keep re-testing. Developers copy JSON more than anyone and lose it just as fast. Relic is an encrypted, searchable memory for everything you copy. It auto-tags JSON, code, and tokens on your device, keeps them forever, and syncs across machines, all end-to-end encrypted and open source. Validate here for free, then keep the payload for good.
Frequently asked questions
How do I check if my JSON is valid?
Paste it in and the tool tells you instantly whether it parses, using the same strict engine your browser ships (JSON.parse). Valid JSON gets a green check plus a count of object keys and array items; invalid JSON gets the exact error.
Why is my JSON invalid?
The usual culprits are a trailing comma after the last item, single quotes instead of double quotes, unquoted keys, comments (JSON does not allow them), or a missing bracket. When parsing fails, this tool shows the error message and the line and column where the parser gave up, so you can jump straight to it.
What is the difference between a JSON validator and a JSON formatter?
A validator only answers one question: is this legal JSON, and if not, where does it break. A formatter re-indents valid JSON to make it readable. This page focuses on validation with precise error locations. If you want pretty-printing too, use our JSON formatter.
Does JSON allow comments or trailing commas?
No. Strict JSON, which is what browsers and most APIs use, forbids both comments and a comma after the final element. Relaxed variants like JSON5 or JSONC allow them, but they are not standard JSON and will fail here, which is correct behavior.
Is it safe to paste JSON with real data in here?
Yes. Validation runs entirely in your browser, nothing is uploaded, so tokens and customer data in an API response never leave your machine.