JSON Validator
Validate JSON online, find syntax errors and try to automatically fix common JSON formatting problems.
JSON Validator
Use our free JSON Validator to check whether your JSON data contains valid syntax. Paste your JSON into the editor and instantly find out whether it is valid or contains syntax errors.
If your JSON is invalid, use the Try Fix feature to automatically attempt to repair common JSON mistakes. After the repair, you can validate the corrected JSON again.
How to Validate JSON
- Paste your JSON into the input box.
- Click Validate JSON.
- If the JSON is valid, you will see a success message.
- If it is invalid, the tool displays an error message.
- Use Try Fix to attempt automatic repair.
- Review the repaired JSON.
- Click Validate JSON again to confirm it is valid.
What Is a JSON Validator?
A JSON Validator checks whether a JSON document follows the syntax rules required by JSON.
JSON uses objects, arrays, strings, numbers, Boolean values and null. Incorrect quotation marks, missing commas, invalid property names and trailing commas can cause JSON parsing errors.
What Does Try Fix Do?
The Try Fix feature attempts to repair several common JSON mistakes.
It can attempt to:
- Convert single quotes to double quotes
- Add quotes around unquoted object keys
- Remove trailing commas
- Convert smart quotes
- Remove common comments
- Normalize values such as
True,FalseandNone - Repair some common missing-comma situations
Because automatic repair can sometimes change the intended data, always review and validate the repaired JSON before using it in production.
JSON Validator vs JSON Formatter
A JSON Validator checks whether JSON syntax is valid.
A JSON Formatter takes valid JSON and makes it easier to read by adding indentation and line breaks.
For best results, use Validate → Try Fix if needed → Format.
❓ FAQ
What is a JSON Validator?
A JSON Validator checks whether JSON data follows valid JSON syntax.
How can I validate JSON online?
Paste your JSON into the tool and click Validate JSON. The tool will tell you whether the JSON is valid or contains a syntax error.
Can this tool fix invalid JSON?
Yes. The Try Fix feature attempts to repair common JSON syntax problems automatically.
Can Try Fix repair every JSON error?
No. Automatic repair is best-effort. Complex or ambiguous errors may require manual correction.
What JSON errors can Try Fix handle?
It can attempt to handle common issues such as single quotes, unquoted object keys, trailing commas, smart quotes, comments and some missing commas.
Is the repaired JSON automatically validated?
Yes. After attempting repairs, the tool parses the repaired result. If it becomes valid JSON, the formatted result is displayed.
Is this JSON Validator free?
Yes. It is free to use and does not require registration.
Does this tool require an API key?
No. JSON validation and repair happen directly in the browser.
Is my JSON sent to a server?
This implementation processes the JSON locally in the browser and does not send the entered JSON to an external API.
Can I download the corrected JSON?
Yes. After a successful validation or repair, click Download JSON.