YAML Formatter & Converter
Format and validate YAML, or convert between YAML and JSON online.
What is YAML?
YAML (YAML Ain't Markup Language) is a human-readable data serialization format widely used for configuration files. It uses indentation to define structure, making it very readable — popular in Docker Compose, Kubernetes, GitHub Actions, and many other tools.
Unlike JSON, YAML supports comments, multi-line strings, and a more concise syntax, making it preferred for configuration files that humans edit frequently.
How to Use
- Paste YAML or JSON in the input panel
- Choose a mode: Format, Validate, YAML→JSON, or JSON→YAML
- Copy or download the result
Frequently Asked Questions
What is the difference between YAML and JSON?
YAML is a superset of JSON and supports comments, multi-line strings, and a more compact syntax. JSON is more strict and universally supported for APIs. YAML is preferred for config files; JSON for data interchange.
Why does YAML use indentation?
YAML uses indentation (not braces like JSON) to define structure. This makes it more readable but means tabs are not allowed — only spaces.
What YAML features are supported?
This tool handles the most common YAML: key-value pairs, nested objects, arrays, strings, numbers, booleans, and null values.
Can I convert YAML to JSON?
Yes. Use the YAML → JSON mode to convert any YAML document to standard JSON.
Is my data sent to a server?
No. All processing is done in your browser.