Validate JSON
Check whether a text is valid JSON and locate the exact error (line and column) when it isn't, as you type.
Processed on your device. Nothing is sent to any server.
Uses the browser's native JSON parser and translates its error message into a readable location (line and column) instead of showing only a technical message.
Use cases
- Quickly checking whether an API response is valid JSON.
- Debugging a JSON that fails to parse in your code.
- Verifying a JSON before pasting it into a configuration file.
How it works
- 1
Paste your JSON
The validation result appears automatically as you type.
Technical details
- It follows strict standard JSON: comments, trailing commas and single quotes aren't allowed.
- The line and column shown are where the parser stops understanding the text; the actual mistake (for example, a missing comma) is usually just before it.
- It validates syntax, not structure: it doesn't check required fields or types the way a JSON Schema would.
Frequently asked questions
Does it catch trailing commas?
Yes, standard JSON doesn't allow trailing commas and this tool flags them as an error, just like JSON.parse would in any browser.