JSON Validate
Paste any JSON. We tell you exactly what is wrong and where — character by character.
What is JSON Validation?
JSON validation checks whether a string conforms to the JSON specification (RFC 8259). A validator parses the input and reports syntax errors — such as a missing comma, an unquoted key, or a trailing comma — with the exact line and character position of the problem.
This tool validates JSON live as you type and shows a green badge when the input is correct, or a red error badge with an explanation when it is not.
How to validate JSON online
- Paste your JSON string into the Input box.
- The validator runs instantly and shows a status badge below the input.
- If there is a syntax error, the message tells you exactly what is wrong and where.
- Fix the error and re-paste — the status updates in real time.
Frequently Asked Questions
What are the most common JSON syntax errors?
Trailing commas after the last item in an array or object, single-quoted strings (JSON requires double quotes), unquoted property keys, and missing colons or commas between key-value pairs.
Does this tool validate JSON Schema?
This tool validates JSON syntax only — it checks whether the string is parseable JSON. JSON Schema validation (checking that a document matches a schema definition) is a separate operation.
What is the difference between JSON and JSON5?
JSON5 is a superset of JSON that allows comments, trailing commas, and single-quoted strings. Standard JSON (RFC 8259) does not allow any of these.
Is my JSON data safe?
Yes. The entire validation runs in your browser using the native JavaScript JSON.parse function. Nothing you paste is transmitted anywhere.