JSON Validator — free online checker
You paste a block of JSON, something breaks, and all you get is a vague "unexpected token" with no idea where to look. A missing comma can cost you twenty minutes of squinting. We added a free tool that does it — JSON Validator — right in your browser.
What it does
Paste your JSON and it instantly tells you whether it's VALID or not. If something is wrong, it points you to the exact line and column of the error and adds a plain, readable hint about what went wrong — a trailing comma, a missing bracket, a stray quote — so you can fix it without guessing.
Nothing leaves your device
It all runs inside your browser. Your JSON is never uploaded to a server and nothing is saved anywhere. You can paste private data, API responses, or config files and close the tab knowing none of it went anywhere.
How to use it
- Open JSON Validator.
- Paste your JSON into the box.
- Read the result — VALID, or the exact line, column and hint to fix the error.
It's free with no limit. There are more small tools on the Apps page.