JSON Validator

Validate JSON syntax instantly with detailed error messages and auto-fix suggestions.

JSON Input

0 chars

Validation

Strict Comments Duplicate Keys

Auto-fix

Fix errors

Ready

What errors can this detect?

Detects missing quotes, trailing commas, wrong brackets, invalid numbers, duplicate keys, unclosed strings, and JSON structure errors.

Is my data secure?

100% secure! All processing happens locally in your browser. No data is sent to any server.

What is strict mode?

Strict mode follows official RFC 8259 JSON specification. Non-strict allows JavaScript-style comments and trailing commas.

Can it fix JSON automatically?

Yes! Auto-fix handles trailing commas, converts single quotes to double quotes, fixes unquoted property names, and more.

What features are included?

Validate, Format, Minify, Copy to clipboard, Download as file, Auto-fix errors, Statistics, Examples, and Detailed error messages with line numbers.

Maximum file size?

Optimized for up to 5MB. For best performance, keep under 1MB.