JSON Validator — RFC 8259 Syntax & Schema Checker
Validate JSON against RFC 8259 with precise error localization, line numbers, and auto-repair suggestions. 100% client-side.
JSON Validator — RFC 8259 Syntax & Schema Checker
JSON Validator is a 100% client-side tool for validating JSON against the RFC 8259 standard. It provides precise error localization with line and column numbers, auto-repair suggestions for common mistakes, and support for JSON Schema draft-07 validation.
How to Validate JSON Online
- Paste or load your JSON data into the input editor.
- Click Validate to check RFC 8259 compliance with detailed error reporting.
- Review errors with precise line/column hints and use the Repair button to fix common issues automatically.
Frequently Asked Questions
Got questions about JSON validation? We've got answers.
What RFC standard does this validator use?
This validator follows RFC 8259 (the official JSON specification). It checks for strict JSON compliance including proper string escaping, number formatting, and structural integrity.
How precise is the error reporting?
Errors include the exact line number, column position, and a human-readable description of what went wrong. Common mistakes like trailing commas or missing quotes are detected with specific repair suggestions.
Can this validator handle large JSON files?
Yes. All validation runs locally in your browser via a Web Worker. Files up to several megabytes work well on modern browsers without slowdown.