JSON Validator

The JSON Validator checks whether your document conforms to the JSON specification and, when it does not, tells you precisely where and why it fails. Instead of a vague 'unexpected token', you get the line, column, and character that broke parsing. Use it to debug malformed API payloads, config files, and copy-pasted snippets in seconds.

• Precise error reporting with line, column, and character offset
• Plain-language explanations of common mistakes like trailing commas
• Instant re-validation as you edit the input
• Detects duplicate keys and other subtle structural issues
• Confirms the top-level type (object, array, string, number, and more)
• Works on documents of any size supported by your browser

1. 1

   Paste your JSON

   Add the JSON you want to check into the input editor.

2. 2

   Read the result

   A clear pass or fail badge appears immediately, along with any error details.

3. 3

   Jump to the error

   If validation fails, the reported line and column point you straight to the problem.

4. 4

   Fix and re-check

   Correct the issue and the validator re-runs to confirm the document is now valid.

• Debugging a 400 response caused by a malformed request body
• Verifying config files before deploying them
• Finding a stray trailing comma or unquoted key in hand-written JSON
• Confirming that data exported from a spreadsheet is valid JSON
• Teaching or learning JSON syntax with immediate feedback