YAML Formatter
Format, validate, and beautify YAML with consistent indentation and error highlighting. Free online tool, no signup.
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Frequently asked questions
- Does this tool support YAML 1.2?
- It handles common configuration YAML (scalars, mappings, block sequences, nested blocks, inline collections) and normalizes indentation. Anchors, custom tags, and multi-document files are not parsed.
- Are comments preserved?
- Yes. Comment lines keep their text and are re-indented with the block they belong to, and a # inside a quoted string or a URL is left alone.
- What does Valid actually check?
- The document is parsed before it is formatted, so an error points at the offending line instead of the tool silently reformatting something it could not read.
- Is my YAML uploaded?
- No. All formatting runs entirely in your browser - nothing is uploaded or stored.
- Why does it reject tabs?
- The YAML spec forbids tab characters for indentation. Replace tabs with spaces and try again.