Lint & Check YAML Style Online
Improve your YAML code quality with this free linter. It detects errors, style issues, and anti-patterns, offering fixes to ensure your YAML files are clean, valid, and follow best practices.
YAML Linter
Check YAML for common errors and style issues
YAML Best Practices
- Use spaces for indentation (not tabs)
- Add a space after colons in key-value pairs
- Avoid trailing whitespace
- Use consistent indentation (2 spaces recommended)
- Quote strings that contain special characters
How YAML Linting Works
YAML linting analyzes your YAML files for syntax errors, style issues, and potential problems. Unlike validation against a schema, linting checks for general best practices, consistency, and common mistakes.
This tool parses your YAML and checks for issues like trailing spaces, inconsistent indentation, deprecated syntax, key ordering, line length violations, and other style concerns that affect readability and maintainability.
What gets checked:
- Syntax errors and parsing issues
- Indentation consistency
- Trailing whitespace
- Line length limits
- Key naming conventions
- Deprecated YAML features
Auto-fix available: Some issues can be automatically fixed. The linter suggests or applies fixes for common problems like whitespace and formatting.
When You'd Actually Use This
Pre-commit checks
Lint YAML before committing. Catch style issues and errors before they enter version control.
CI/CD pipeline validation
Add linting to CI pipelines. Ensure all YAML files meet quality standards before deployment.
Team consistency
Enforce consistent YAML style across team. Everyone follows same conventions for indentation, naming, and formatting.
Legacy file cleanup
Clean up old YAML files. Identify and fix style issues in inherited or legacy configuration files.
Learning YAML best practices
Learn from lint warnings. Understand YAML best practices through linter feedback on your files.
Code review preparation
Fix lint issues before review. Submit clean YAML for code review, focusing discussion on logic not formatting.
What to Know About YAML Linting
Style rules are configurable. Different projects have different conventions. Configure lint rules to match your team's style guide.
Warnings vs errors. Linters report errors (must fix) and warnings (should fix). Errors block deployment, warnings are advisory.
Some rules are opinionated. Style rules (key ordering, quoting) are subjective. Disable rules that don't match your preferences.
Auto-fix is convenient. Many issues can be auto-fixed. Use auto-fix for mechanical changes, review semantic changes manually.
Pro tip: Integrate linting into your editor for real-time feedback. Fix issues as you write instead of batch-fixing later.
Common Questions
What's the difference between linting and validation?
Validation checks against a schema (required fields, types). Linting checks style and best practices (formatting, conventions). Both are important for quality.
Can I customize lint rules?
Yes. Enable/disable specific rules, configure thresholds (line length), and set severity levels based on your project needs.
What issues can be auto-fixed?
Trailing whitespace, indentation, line endings, and formatting issues can typically be auto-fixed. Semantic issues require manual fixes.
Should I fix all warnings?
Fix errors always. Warnings depend on context—some style warnings may be acceptable for your use case. Configure rules to match your needs.
How do I integrate with CI/CD?
Add lint command to your pipeline. Fail the build on lint errors. Many CI systems have YAML lint actions/plugins available.
Does linting catch syntax errors?
Yes. Syntax errors are the first thing linters check. Invalid YAML won't pass linting regardless of style rules.
Is my data secure?
Yes. All linting happens locally in your browser. Your YAML content never leaves your computer.
Other Free Tools
YAML Validator
Free Online YAML Validator
YAML to JSON Converter
Convert YAML to JSON Online
JSON to YAML Converter
Convert JSON to YAML Online
YAML Formatter & Beautifier
YAML Formatter and Beautifier
YAML Minifier & Compressor
YAML Minifier and Compressor
ASCII to Hex Converter
ASCII to Hex Converter: Text to Hexadecimal Translator
Barcode Generator
Free Barcode Generator
Binary to Text Converter
Binary to Text Converter
Free Printable Calendar Maker
Create & Print Your Custom Calendar
Pie Chart Maker
Free Pie Chart Maker Online