To validate JSON, paste it into the JSON Validator. It tells you whether the JSON is valid and, if not, shows the exact line and column of the first error with a plain-language explanation.
Follow along with the free JSON Validator, which runs in your browser, or browse more tools in this category.
How to use the JSON Validator
- Paste your JSON into the validator.
- Run the check.
- If it is invalid, read the line and column and the explanation of what is wrong.
- Fix the problem and validate again until it passes.
Worked example
The text {“a”: 1,} is invalid because JSON does not allow a trailing comma after the last item. Removing the comma makes it valid.
Tips and common mistakes
- Strings and keys must use double quotes, never single quotes.
- JSON has no comments, so remove any // or /* */ lines.
- Numbers cannot have leading zeros, and values like undefined or NaN are not valid JSON.
Frequently asked questions
Does it fix the JSON for me?
It finds and explains the error. You make the correction, then validate again.
What is the most common JSON error?
A trailing comma or a missing quote are the most frequent.
Is it private?
Yes. Validation happens in your browser.