JSON Validator
Developer ToolsCheck JSON and find the exact error line
Embed this tool on your websiteFree
- Choose how tall the frame should be.
- Press Copy code.
- Paste it into your page, blog, WordPress or Notion HTML block.
The tool runs inside your visitor's browser, nothing is uploaded, and a small "Powered by ToolCloak" line stays under it. The second line (script) is optional: it makes the frame fit the tool's height.
Similar tools you may like
History
All history →JSON Validator — at a glance
Validate any JSON and see the exact line and column of the first error.
How to use it — step by step
Any JSON text — an object, an array or a single value.
Paste your input
Paste or type your content into the big input box. Try a sample if you want to see it work.
Choose options
Pick the mode and options that fit what you need.
Validate JSON
Press the button. The result is created instantly on your device.
Copy the result
Check the output and press Copy to use it anywhere.
Pro tips
Small things that make the result better.
Quick facts
Frequently Asked Questions
What does the line and column mean?+
It points to where the parser first got confused. The real mistake is usually just before that spot.
Are comments allowed in JSON?+
No. Standard JSON does not allow comments or trailing commas.
Is my data safe?+
Yes. Everything runs inside your own browser. Your text, files and images are never uploaded to any server.
Is this tool really free?+
Yes — completely free, no signup, no watermark and no usage limit.