YAML Formatter
Format and beautify YAML documents with consistent indentation and optional key sorting. Perfect for infrastructure configs, GitHub Actions files, Docker Compose snippets, and readable diffs in version control.
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What is YAML Formatter?
The YAML Formatter parses YAML text and outputs it with consistent indentation and structure. It validates the YAML syntax and reports errors with line numbers and descriptions. The tool handles nested mappings, sequences, multi-line strings, and anchors. All processing happens in the browser.
How does YAML Formatter work?
This tool parses YAML using a JavaScript YAML parser, validates the syntax, and re-serializes it with configurable indentation. If parsing fails, it shows the line number and error description. The formatted output preserves all data while standardizing the visual structure.
Key Features
- Formats YAML with consistent indentation
- Validates YAML syntax with error messages
- Configurable indent size
- Handles nested mappings and sequences
- Supports multi-line strings and anchors
- Copy formatted YAML to clipboard
- Download as .yml file
- Runs in the browser with no uploads
Common Use Cases
Cleaning up messy YAML config files
Reformat a YAML file with inconsistent indentation for readability.
Validating Kubernetes manifests
Check that a Kubernetes YAML file is syntactically valid before applying it.
Standardizing CI/CD configs
Format a GitHub Actions or GitLab CI YAML file with consistent style.
Debugging YAML syntax errors
Paste broken YAML and get the exact line number and description of the error.
How to Use This Tool
Paste YAML
Enter YAML text in the input area.
Set indent
Choose the indent size (2 or 4 spaces).
Format
Click Format. The tool validates and reformats the YAML.
Copy or download
Copy the formatted YAML or download it as a .yml file.
Pro Tips
- 1
2-space indentation is the standard YAML convention.
- 2
If formatting fails, the error message shows the line number.
- 3
The tool handles YAML anchors (&) and aliases (*) correctly.
- 4
For Kubernetes configs, always validate before applying with kubectl.
Frequently Asked Questions
Will formatting change the YAML data?
No. Formatting only changes whitespace and indentation. The data, key order, and values are preserved.
What if my YAML has a syntax error?
The tool shows the line number and a description of the error so you can fix it.
Is my YAML uploaded to a server?
No. All parsing and formatting happens in your browser. Nothing is transmitted.
Does it handle YAML anchors?
Yes. The tool correctly parses and preserves YAML anchors (&) and aliases (*).
Can I choose tabs instead of spaces?
YAML requires spaces for indentation. The tool uses spaces with a configurable indent size.