YAML Format Guide

About YAML Format

YAML (YAML Ain't Markup Language) is a human-readable data serialization standard created by Clark Evans in 2001. It uses indentation-based structure with key-value pairs, lists, and nested objects. YAML is widely adopted for configuration files in tools like Docker, Kubernetes, Ansible, GitHub Actions, and many programming frameworks.

YAML's clean, minimal syntax makes it easy to read and write compared to alternatives like JSON or XML. It supports complex data structures including nested mappings, sequences, scalars, and even anchors and aliases for referencing repeated content. The .yaml extension is the official recommendation, while .yml is a common shorter alternative.

Available Conversions

YAML Features

• Human-Readable: Clean syntax with minimal punctuation and indentation-based structure
• Data Types: Strings, integers, floats, booleans, null, dates, and timestamps
• Collections: Sequences (lists) and mappings (dictionaries) with arbitrary nesting
• Multi-Document: Multiple documents in a single file separated by ---
• Anchors & Aliases: Reference and reuse repeated data structures
• Comments: Full comment support with # character
• Unicode: Full UTF-8 encoding support
• JSON Superset: YAML 1.2 is a superset of JSON — valid JSON is valid YAML
• Multi-line Strings: Literal (|) and folded (>) block styles for long text
• Tags & Types: Custom type annotations for specialized parsing

Common Uses

• Docker: docker-compose.yaml for container orchestration
• Kubernetes: Pod, Service, Deployment manifests
• Ansible: Playbooks, roles, and inventory files
• GitHub Actions: CI/CD workflow definitions (.github/workflows/)
• OpenAPI/Swagger: API specification files
• Static Site Generators: Jekyll, Hugo configuration and front matter
• Spring Boot: application.yaml configuration
• Helm Charts: Kubernetes package manager templates