Question 1

What is YAML?

Accepted Answer

YAML (YAML Ain't Markup Language) is a human-readable data serialisation format commonly used for configuration files. It uses indentation to represent structure and is the standard format for Docker Compose files, Kubernetes manifests, GitHub Actions workflows, and many application config files.

Question 2

What is the difference between YAML and JSON?

Accepted Answer

YAML is a superset of JSON — all valid JSON is valid YAML. YAML is generally more readable for humans because it uses indentation instead of braces and brackets, and it supports comments. JSON is more widely supported in APIs and is faster to parse.

Question 3

Why is my YAML invalid?

Accepted Answer

Common YAML errors include: inconsistent indentation (mixing tabs and spaces), missing spaces after colons in key-value pairs, unquoted strings containing special characters like : or #, and duplicate keys. YAML is indentation-sensitive so alignment must be consistent throughout the file.

Question 4

Is my YAML data sent to a server?

Accepted Answer

No. All validation and processing happens entirely in your browser. Your YAML data never leaves your device and is auto-saved to localStorage so it persists between sessions.

Question 5

Can I validate Docker Compose and Kubernetes files?

Accepted Answer

Yes. This tool validates the YAML structure of any .yaml or .yml file including Docker Compose, Kubernetes manifests, Helm charts, and GitHub Actions workflows. Note that it validates YAML syntax only — it does not validate against Docker or Kubernetes schemas specifically.

YAML Editor & Validator — Beautify, Minify, Tree View