JSON Validator

About this tool

Check whether your JSON is valid. Valid JSON is confirmed; invalid JSON shows the exact parser error so you can fix it.

Example

Input: {"a":1}

Output: Valid JSON

Privacy

This tool runs entirely in your browser. Your data is processed locally and never uploaded to a server.

How to use this tool

1. Paste your JSON into the input box.
2. Click the validate button to check it.
3. Read the result and compare any error message with your JSON.
4. Fix the highlighted mistake, then validate again.

Step by step, what happens

1. The tool reads the text you paste and sends it to a JSON parser.
2. If the text follows JSON rules, the tool confirms that it is valid.
3. If something is wrong, the parser returns the exact error message and the location of the problem.
4. You correct the issue and run validation again until the JSON passes.

Worked example

Here is a small JSON object that a developer might paste while checking an API response body.

Input: { "name": "Ava", "active": true }

1. Paste the object into the validator and run the check.
2. The parser sees a proper JSON object with a string and a boolean value.
3. The tool reports that the JSON is valid.

Tips and common mistakes

• Use double quotes around all JSON keys and string values. Single quotes are not valid in JSON.
• Make sure trailing commas are removed, because JSON does not allow a comma after the last item.
• Check that booleans are written as true or false, and that null is written exactly as null.
• If the tool shows an error position, look at the character right before that spot first, since the real mistake is often just before the parser stops.

Frequently asked questions