Advanced syntax and schema validation with detailed error reporting
Professional-grade validation toolkit for modern development
Instantly validate JSON syntax with precise error location and detailed explanations
Validate JSON against custom schemas with comprehensive compliance reporting
Advanced error detection with line-by-line analysis and fix suggestions
Lightning-fast validation even for large files with optimized processing algorithms
Upload and validate JSON files up to 100MB with batch processing capabilities
All validation happens in your browser - complete privacy and security guaranteed
Complete JSON toolkit for professional development
Common questions about JSON validation
It verifies that your text is valid JSON according to RFC 8259: proper key quoting, correct bracket/brace matching, valid data types, no trailing commas, and correct escape sequences. It catches errors that would cause JSON.parse() to fail.
Trailing commas after the last item, single quotes instead of double quotes, unquoted keys, missing commas between items, and comments (JSON doesn't support them). Our validator pinpoints the exact line and character position of each error.
All valid JSON is valid JavaScript, but not vice versa. JavaScript allows single quotes, unquoted keys, trailing commas, and comments — none of which are valid JSON. Always validate if your JSON will be consumed by non-JavaScript parsers.
Yes — paste any text and the validator instantly tells you whether it's valid JSON. This is useful for debugging API responses, checking webhook payloads, and verifying that your serialization code produces correct output.
No. Validation runs entirely in your browser using JavaScript. Your JSON data is never sent anywhere, making it safe to validate responses containing sensitive data, tokens, or user information.