YAML Validator
Validate YAML syntax and check for formatting errors
Enter or upload YAML data to validate
About this Tool
YAML Validator is a free, privacy-first tool built for developers. Validate YAML syntax and check for formatting errors
â100% Client-Side: All processing happens in your browser. No data is ever sent to our servers.
âFast & Efficient: Instant results with no server roundtrips or delays.
âFree Forever: No sign-up, no limits, no hidden fees. Use as much as you need.
âFile Support: Upload files directly or paste content. Your choice.
âHistory: Your recent conversions are saved locally for quick access.
Disclaimer
This tool is provided for informational and educational purposes only. All processing happens entirely in your browser - no data is sent to our servers. While we strive for accuracy, please verify critical data before use in production environments. FormatKit is not responsible for any data loss, corruption, or issues resulting from tool usage.
Keyboard Shortcuts
How to Use YAML Validator
Upload a YAML file or paste your YAML data into the input field and it will be automatically validated. The validator checks for YAML syntax errors and provides detailed error messages with line numbers.
Features
- Instant validation as you type
- Detailed syntax error messages with line numbers
- Structure analysis (object, array, or mixed)
- Document type detection
- Preview of parsed structure
- Best practices warnings
Common YAML Issues Detected
- Indentation errors: Inconsistent spaces or mixing tabs and spaces
- Syntax errors: Missing colons, invalid characters, or malformed lists
- Quote issues: Unmatched quotes or incorrect string escaping
- Duplicate keys: Same key defined multiple times in an object
- Invalid anchors: Undefined or incorrectly referenced anchors
FAQ
Q: Is my data secure?
Yes! All YAML validation happens entirely in your browser. Your data never leaves your device.
Q: What's the maximum file size?
The validator can handle YAML files up to 10MB. For optimal performance, we recommend files under 5MB.
Q: Does this validator support all YAML features?
Yes, this validator supports YAML 1.2 specification including anchors, aliases, multi-line strings, and all standard data types. Complex YAML features like custom tags are also supported.
Q: Can I use this to convert YAML to JSON?
While this tool validates YAML syntax, for conversion use our dedicated YAML to JSON Converter.
Disclaimer: This validator checks YAML syntax and structure. For production systems, always implement comprehensive validation that includes schema validation and business logic rules specific to your use case. This tool is provided as-is for convenience and educational purposes.