YAML Formatter
YAML FormatterFormat & Validate
About YAML
YAML (YAML Ain't Markup Language) is a human-readable data serialization format commonly used for configuration files. It uses indentation to represent hierarchy and is widely used in DevOps, Docker Compose, Kubernetes, and many applications.
Related Tools
What is YAML?
YAML (YAML Ain't Markup Language) is a human-readable data serialization format. It's designed to be easy to read and write, making it popular for configuration files across many applications and platforms.
YAML uses indentation to represent hierarchy, making it visually clean and intuitive. It's widely used in DevOps tools like Docker Compose, Kubernetes, Ansible, and many CI/CD pipelines.
This free tool helps you format, beautify, and validate YAML documents. It provides statistics about your document structure and supports customizable indentation options.
Features
Format & Beautify
Transform messy YAML into clean, properly indented format with consistent spacing.
Validation
Instantly detect syntax errors and structural issues in your YAML documents.
Customizable Indentation
Choose between 2 spaces, 4 spaces, or tabs for indentation to match your style.
Document Statistics
View line count, key count, arrays, maximum nesting depth, and file size.
Download & Copy
Download the formatted YAML as a file or copy it directly to your clipboard.
Sample Data
Load a sample YAML document to see how the formatter works with real data.
YAML Syntax Guide
Key-Value Pairs: Use colons to separate keys from values (key: value).
Indentation: Use spaces (not tabs in standard YAML) to represent hierarchy.
Lists: Use hyphens followed by a space for list items (- item).
Comments: Start comments with a hash symbol (#).
Strings: Quotes are optional for most strings, required for special characters.
Multi-line: Use | for literal blocks or > for folded blocks.
Frequently Asked Questions
What is the difference between YAML and JSON?
YAML is more human-readable and uses indentation for structure, while JSON uses braces and brackets. YAML supports comments, JSON doesn't. YAML is a superset of JSON, meaning valid JSON is also valid YAML.
Why is indentation important in YAML?
YAML uses indentation to represent the hierarchy of data. Incorrect indentation will cause parsing errors or incorrect data structure interpretation. Always use consistent spacing.
Can I use tabs for YAML indentation?
The official YAML specification discourages tabs and recommends using spaces for indentation. While some parsers may accept tabs, using spaces ensures maximum compatibility.
Is my data secure?
Yes. All processing happens entirely in your browser using JavaScript. Your YAML data never leaves your device and is not sent to any server.