JSON Validator with clear error messages
Paste JSON to check it against the JSON standard. Valid JSON gets a green tick and a summary; invalid JSON gets the exact line and column, the line highlighted and a hint on how to fix it.
How to use the JSON validator
- Paste your JSON or drop a file on the editor.
- Check the status bar: a green tick for valid JSON, or the error with its line and column.
- Press Go to error to jump straight to the problem in the editor.
- Fix it by hand, or press Repair to fix common mistakes automatically.
What you get
- Strict checking against the JSON standard (RFC 8259)
- Line and column of the first error
- A hint for the likely cause, such as a missing comma
- A summary of valid JSON: size, keys and nesting depth
About the JSON validator
Hints, not just errors
"Unexpected token" rarely helps. This validator recognises the usual mistakes, such as trailing commas, single quotes, unquoted keys, comments, a missing comma or a bracket that is never closed, and says what to change.
Validation as you type
The result updates while you edit, so you can fix one error and immediately see whether anything else is wrong.
Repair in one click
When the JSON came from a config file, a log or a Python script, Repair fixes the common problems together and lists each fix it made.
Frequently asked questions
- Why is my JSON invalid when JavaScript accepts it?
- JavaScript object syntax is looser than JSON. JSON needs double quotes around every key and string, and does not allow comments, trailing commas or values like undefined.
- Does it validate against a JSON Schema?
- Not yet. It checks that the text is valid JSON. Schema validation is on our list for a future update.
- Is it safe to validate private data?
- Yes. Validation runs in your browser and the JSON is never uploaded or stored.