JSON Validator
Validate JSON and find syntax errors with line details. — free, fast and private.
How to use JSON Validator
- Paste the JSON you want to check into the box.
- Click Validate JSON.
- Read the result: valid JSON shows its type and key or item count; invalid JSON shows the error and its line and column.
Note: this tool runs in your browser. Nothing is uploaded.
Frequently Asked Questions
What does the JSON Validator check?
It checks whether your text is syntactically valid JSON and reports the exact parser error, including line and column when available.
Why is my JSON invalid?
The most common causes are missing commas, trailing commas, single quotes instead of double quotes, and unquoted keys. The error message points at the problem spot.
Is my data uploaded to a server?
No. This tool runs entirely in your browser and your input is never uploaded to a server.
Can I use this tool on my phone?
Yes, the tool is fully mobile-friendly and works in any modern browser.