JSON Validator

Is your JSON actually valid? Paste it in and find out immediately — with the exact line number and reason if something's broken, not just a generic error.

What is JSON Validator?

A JSON Validator checks whether your JSON data follows the correct syntax specification. It provides detailed error messages showing exactly where and what went wrong. Essential for debugging API integrations and configuration files.

Formula

Input: JSON string → Parse attempt → Valid (green) or Invalid (red with error details)

How to Calculate

Paste your JSON into the input area.
The validator checks your JSON automatically.
See a green badge if valid or red badge with error details if invalid.
Fix any errors and re-validate.

Example

Input: {"name":"John","age":30,} has a trailing comma after 30. The validator reports: "Expected a value at line 1, column 26" pinpointing exactly where the fix is needed.

Key Benefits

Instant JSON validation
Detailed error messages with location
Auto-validation on input changes
Free no sign-up required

Common Mistakes to Avoid

Using comments in JSON (not supported)
Mixing data types in arrays
Forgetting to escape double quotes within strings

Pro Tips

Validate JSON before using it in production
Use the formatted output to find structural issues
Combine with JSON Formatter for the best experience

Key Terms Explained

Validation: Checking JSON syntax correctness
Parse: Interpret JSON string as data
Syntax error: Violation of JSON formatting rules
Schema validation: Checking data structure against a schema

Common Use Cases

Validating API payloads before sending
Checking configuration files
Debugging JSON parsing errors
Verifying exported data integrity

Frequently Asked Questions

What does JSON validation check?

Validation checks for correct JSON syntax: proper quotes, commas, brackets, colons, and data types. It identifies the exact location of any syntax error.

Can it validate very large JSON files?

Yes, but very large files may cause browser performance issues. For extremely large JSON (100MB+), consider a command-line tool instead.

What are common JSON errors?

Common errors include: trailing commas, missing quotes on keys, single quotes instead of double quotes, extra commas in arrays, and unescaped special characters in strings.

Related Tools

Aspect Ratio Calculator

Bandwidth Calculator

Download Time Calculator

Cloud Hosting Cost Calculator

CDN Cost Calculator

API Monetization Calculator