Validate JSON online instantly with this fast and free JSON validator. Check JSON syntax, detect errors, and fix issues in seconds. This tool also works as a JSON syntax checker, making it ideal for debugging API responses and configuration files. Runs entirely in your browser for maximum speed and privacy.
Used by developers to quickly detect and fix JSON errors in real-time.
⭐ Bookmark this page to quickly validate JSON and fix errors anytime.
A JSON validator is a tool that checks whether your JSON data is valid and correctly formatted. It helps identify syntax errors such as missing quotes, trailing commas, or invalid structures, making debugging faster and easier. It also works as a JSON syntax checker to ensure your data structure is correct and error-free.
You can also use the fix feature to automatically correct common JSON errors.
Here’s an example of invalid JSON and the detected error:
{"name":"John","age":30,}Trailing comma after last property
Try validating your own JSON above to detect errors instantly.
You can also use our JSON Formatter to format valid JSON into a clean, readable structure.
Compare JSON, generate schemas, and extract fields faster with these related tools.
Format valid JSON into a clean, readable structure.
Compare two JSON objects and highlight differences.
Generate a JSON Schema from sample data.
Find JSONPath expressions to access nested fields.
Convert JSON data into XML format locally without any data upload
Paste your JSON into the input field and click “Validate” to validate JSON online. This JSON validator acts as a JSON error checker: if something is wrong, you’ll see a clear message and (when possible) line and column details.
This JSON syntax checker flags common JSON syntax errors like missing quotes, trailing commas, unquoted keys, invalid characters, mismatched brackets, and malformed structures. When possible, it points you to the error location so you can fix it fast.
Yes. Click “Fix Common Errors” to automatically correct common issues like single quotes, trailing commas, unquoted keys, and comments. Always review the output afterwards, especially for complex payloads. You can format valid JSON using our JSON Formatter.
Yes. This JSON validator is free to use with no signup and no usage limits.
No. Validation runs locally in your browser, so your JSON is not uploaded or stored.
Yes. Paste JSON from an API response to run a quick JSON error checker pass, then fix the reported syntax issues and re-validate before parsing in your app.
Use the tool above to check JSON syntax and fix errors instantly.