API JSON Validator
Validate JSON responses from REST APIs. Ensure your API endpoints return properly formatted JSON.
💡 Paste your JSON and it will be validated automatically. The validator checks for syntax errors and provides helpful suggestions to fix common issues.
Frequently Asked Questions
What does this JSON validator check?
This tool validates JSON syntax according to the JSON specification (RFC 8259). It checks for proper formatting, matching brackets, valid strings, numbers, and data types.
Why is my JSON invalid?
Common JSON errors include: missing or extra commas, unquoted keys, single quotes instead of double quotes, trailing commas, and unescaped special characters in strings.
Can I validate large JSON files?
Yes! The validator works entirely in your browser and can handle large JSON files. However, for very large files (10MB+), it may take a moment to process.
Is my data secure?
Yes, all validation happens in your browser. Your JSON data is never sent to any server.
What's the difference between JSON validation and linting?
Validation checks if JSON is syntactically correct. Linting (like JSONLint) also checks for best practices and style issues. This tool performs syntax validation.