JSON Validator
Check whether your JSON is valid and inspect its structure.
A JSON validator confirms whether your input is valid JSON and, if so, reports its root type (object, array, etc.) and top-level keys. Invalid input produces a clear error.
How to Use the JSON Validator
- Paste your JSON. Enter the JSON to validate.
- Check the result. See whether it is valid and what its structure is.
This tool processes your input locally in your browser. Nothing is uploaded.
What Is JSON Validator?
A JSON validator tells you whether your data is correctly structured before you use it in code or an API.
Why validate JSON?
Invalid JSON causes errors in your application. Validating early catches missing commas, wrong quotes and unmatched brackets before they break things.
What you get back
The validator reports whether the input is valid, the root type, and the number of top-level keys or items — useful for quick structure checks.
Key Features
- Validates JSON
- Reports root type
- Shows top-level keys
- Clear error messages
Examples
- A valid object returns "Valid" with its key count.
- An array of items returns the array length.
Common Use Cases
- Pre-deploy validation
- API testing
- Config checks
Tips & Best Practices
- Watch for trailing commas and single quotes — both invalidate JSON.
Limitations
- Reports structure, not semantics; valid JSON can still be logically wrong.
Related Tools
Related Articles
JSON Formatter – Complete Guide & Free Online Tool A JSON formatter takes minified or messy JSON and reformats it with clean indentation so it is easy to read. It also validates your input and shows meaningful errors when the JSON is invalid. Free online tool included. Read guide → JSON Validator – Complete Guide & Free Online Tool A JSON validator confirms whether your input is valid JSON and, if so, reports its root type (object, array, etc.) and top-level keys. Invalid input produces a clear error. Free online tool included. Read guide → JSON Minifier – Complete Guide & Free Online Tool A JSON minifier strips all unnecessary whitespace from your JSON, producing a compact form that is smaller and faster to transfer while remaining valid. Free online tool included. Read guide → JSON to CSV – Complete Guide & Free Online Tool A JSON to CSV converter turns an array of objects into a comma-separated table, using the union of all keys as columns. Free online tool included. Read guide →
Frequently Asked Questions
What is a JSON validator?
It checks whether your input is valid JSON and reports its structure.
Why is my JSON invalid?
Usually missing commas, trailing commas, single quotes or unmatched brackets.
Is it free?
Yes, and it runs locally.