JSON Validator

Validate JSON online

Check JSON syntax locally and find errors with clear line and column details.

What does JSON validation check?

Validation confirms that a document follows strict JSON syntax: quoted property names, balanced brackets, valid escape sequences, and supported values.

The validator runs in your browser. API responses, configuration files, and other sensitive payloads are not uploaded to our servers.

How to use this tool

Paste, drop, upload, or load a JSON document.
Validation runs locally after you pause typing.
Use the reported line and column to correct the first syntax error.

Example

Input

{"name":"Ada","active":true}

Result

Valid JSON.

Common problems

Single quotes are JavaScript syntax, not strict JSON strings.
A trailing comma before } or ] makes the document invalid.
Comments and unquoted property names require Repair before validation.

Useful tips

Property names and strings must use double quotes.
Trailing commas and comments are not valid JSON.
Use Repair when you want to preview corrections.