YAML Formatter & Validator

YAML is the language of configuration: Kubernetes manifests, Docker Compose files, CI/CD pipelines, Ansible playbooks, and many application settings are written in it. Because YAML uses indentation for structure, a single misplaced space can break a file or silently change its meaning.

This YAML formatter checks your file for errors and re-indents it consistently. Unlike many converters, it keeps your comments, so you can safely format files you commit to version control.

• Consistent indentation

  Re-indents every mapping and list with 2, 3, or 4 spaces, so the structure is easy to read.

• Keeps your comments

  Comments, blank lines between entries, anchors, aliases, tags, and quoting styles are preserved.

• Precise validation

  Bad indentation, tabs, duplicate keys, undefined aliases, and unclosed quotes or brackets are reported with line and column.

• Real-world YAML

  Handles Kubernetes manifests, Docker Compose files with merge keys (<<), GitHub Actions workflows, and multi-document files.

• Tree view

  Explore the parsed data, with aliases and merge keys resolved, in a collapsible tree.

• Private by design

  Everything runs locally in your browser. Your YAML, including any secrets, is never uploaded.

server:
     host: localhost   # local only
     ports:
     - 80
     - 443
     tls: {enabled: true}

server:
  host: localhost # local only
  ports:
    - 80
    - 443
  tls: {enabled: true}

The indentation is normalized, and the comment and flow mapping are kept.

1. Paste your YAML into the Input editor, or upload or drop a .yaml or .yml file.
2. The tool validates it instantly and shows any error with its line and column.
3. Choose Beautify and your indentation, or Minify for a single line.
4. Copy the result or download it as a .yaml file.