YAML Validator
Validate YAML syntax with detailed error messages. Auto-formats valid YAML and highlights the exact error location for invalid input.
Examples
Valid YAML config
In:server:
host: localhost
port: 8080
debug: true
dat...
Invalid YAML (tab indentation)
In:server:
host: localhost
port: 8080
YAML with anchors
In:defaults: &defaults
timeout: 30
retries: 3
productio...
How to Use YAML Validator
- Paste or type your YAML in the input area.
- Click "Validate" or use an example to test.
- If the YAML is valid, the formatted output appears on the right.
- If invalid, an error message shows what went wrong and the approximate location.
- Click "Copy" to copy the formatted result.
What is YAML?
YAML (YAML Ain't Markup Language) is a human-friendly data serialization format commonly used for configuration files (Docker Compose, Kubernetes, CI/CD pipelines, Ansible). It uses indentation to represent structure, making it easy to read but sensitive to whitespace errors. Unlike JSON, YAML supports comments, multi-line strings, and anchors/aliases for reusing values.