JSON Validator
Check whether text is syntactically valid JSON and see its parsed shape.
This tool runs entirely in your browser. Your files are never uploaded to a server.
Valid: The input is syntactically valid JSON.
- Top-level type: object
- 2 top-level properties
Clear the entered value before starting another check. Validation runs locally and does not check against any external registry, server, or account.
What this tool does
Parses the entered text as JSON and reports whether it is syntactically valid, along with its top-level type and size.
How to use it
Paste or type JSON into the textarea. The checker parses it immediately and shows a pretty-printed, copyable version alongside the top-level type — object, array, or a scalar value.
Example
Entering {"name": "Quiklio", "active": true} returns valid, reports an object with 2 top-level properties, and offers a 2-space indented copy.
Validation
Parsing follows the standard JSON grammar exactly as the browser's JSON.parse implements it; a single misplaced comma, unquoted key or trailing comma is enough to fail.
How to interpret the result
A valid result only confirms JSON syntax — it does not check the data against any schema, required fields or expected types, and it does not detect duplicate keys, which JSON.parse silently keeps the last of.
Limitations
This checker validates syntax only; use a dedicated JSON Schema validator if you need to confirm that specific fields, types or value ranges are present.
Privacy
All processing uses local browser APIs and this tool does not upload the values you enter.
Frequently Asked Questions
- What does JSON Validator do?
- Parses the entered text as JSON and reports whether it is syntactically valid, along with its top-level type and size.
- How does it handle invalid input?
- Parsing follows the standard JSON grammar exactly as the browser's JSON.parse implements it; a single misplaced comma, unquoted key or trailing comma is enough to fail.
- Is entered data uploaded?
- All processing uses local browser APIs and this tool does not upload the values you enter.