YAML Formatter & Validator Online

Format and validate YAML with consistent 2-space indentation, key alignment, and comment preservation.

How to Use

  1. 1

    Paste YAML

    Paste your YAML configuration file content.

  2. 2

    Format

    Click Format to normalize indentation to 2 spaces.

  3. 3

    Copy

    Copy the clean, properly formatted YAML.

FAQ

How do comments work in YAML?

YAML comments start with # and continue to the end of the line. They can appear on their own line or after a value. This formatter preserves existing comments during reformatting.

What indentation does YAML use?

YAML uses spaces (never tabs) for indentation. This formatter normalizes to 2 spaces per level, which is the standard for Docker Compose, Kubernetes manifests, and GitHub Actions workflows.

Why is my YAML invalid?

Common YAML errors include: using tabs instead of spaces, incorrect indentation levels, unquoted strings with special characters (: { } [ ]), and duplicate keys. This tool highlights the exact error location.