About YAML Formatter

Format and prettify YAML documents. Part of the DevTools Surf developer suite. Browse more tools in the YAML collection.

Use Cases

• DevOps engineers standardizing YAML formatting across team repos
• Developers cleaning up messy Ansible playbook files
• Platform engineers formatting Terraform YAML variable files
• Technical writers creating readable YAML examples for documentation

Tips

• Set a consistent indent width of 2 spaces for YAML best practices
• Format multi-line strings to use block scalar style for readability
• Check that comments are preserved in the formatted output

Fun Facts

• YAML is a strict superset of JSON, meaning every valid JSON document is also a valid YAML document.
• The YAML specification (version 1.2) is 86 pages long, making it one of the most complex data serialization format specs.
• YAML's indentation-based syntax was inspired by Python, reflecting the early 2000s trend toward whitespace-significant languages.

FAQ

What style conventions does the formatter follow?

Two-space indentation, no trailing whitespace, unified flow/block style. The goal is output compatible with yamllint's default config.

Will it preserve my comments?

Yes — comments stay attached to the line above or to the same line, whichever matches the original position. Structural comments at the top of the file are kept at the top.

Can I force flow style or block style?

Toggle between them. Flow style is compact (`{key: value}`) and matches JSON; block style is the multi-line hierarchical form most YAML files use.

Does it sort keys?

Off by default — YAML often encodes configuration order (e.g. Kubernetes manifests rely on order). Toggle 'sort keys' if you want alphabetical.