Best uses
Configuration files, CI/CD, Kubernetes-style configuration and structured data review.
YAML Formatter & Validator
Format, beautify and check YAML online. Detect tabs, indentation problems, duplicate keys and other common YAML structure issues.
Free YAML Formatter & Validator
This free YAML Formatter and Validator helps developers clean up YAML configuration files and identify common indentation and structure problems directly in the browser.
What is YAML?
YAML is a human-readable data serialization format commonly used for configuration files, application settings, Docker Compose files and CI/CD configuration.
What Does This YAML Tool Check?
- Tab characters used for indentation
- Inconsistent indentation
- Duplicate mapping keys
- Malformed key-value pairs
- Invalid list indentation
- Unbalanced brackets
- Unclosed quotes
- Common YAML structure problems
Important:
YAML has many advanced features and dialect differences.
This browser-based checker focuses on common YAML syntax
and configuration patterns. It is not a complete replacement
for a full YAML parser.
Example YAML
name: Daily Wishes Hub
version: 1.0
server:
host: localhost
port: 8080
features:
- blog
- tools
- search
database:
enabled: true
name: blog_system
How to Format YAML
- Paste your YAML into the input box.
- Select your preferred indentation.
- Click Format YAML.
- Review the formatted YAML.
- Copy the result.
Frequently Asked Questions
Why is YAML indentation important?
YAML uses indentation to represent structure. Incorrect indentation can change the meaning of a document or make it invalid.
Can YAML use tabs?
YAML indentation should use spaces rather than tab characters. This tool warns when tab characters are detected.
Does this tool execute YAML?
No. The tool only analyzes YAML text in your browser. It does not execute configuration files or connect to external services.
Is this YAML Formatter free?
Yes. The YAML Formatter & Validator is free to use online.