No. Parsing and formatting happen locally in your browser; nothing is sent to a server.

YAML Formatter

Q: How do I format YAML online?

Paste YAML into the left panel. It is parsed and printed back with consistent block-style indentation on the right. Pick 2 or 4 spaces, a line width, and optionally sort keys or quote all strings, then copy or download the result.

Q: Does the YAML formatter keep comments?

The formatter retains comments where possible, though their position may change. Review the output and keep your original.

Q: Will formatting change my values?

It refuses to format numeric scalars whose spelling it cannot safely retain, rather than silently changing them. YAML 1.1 and 1.2 interpret some scalars differently. Custom tag semantics cannot be checked; always review the output.

Q: Why can't I quote all strings?

Quoting plain values such as yes can change their meaning in YAML 1.1. As a precaution, the option also refuses digit-leading plain strings such as 2024-01-15 or 1.2.3. Disable it or edit these values deliberately.

Q: Can it format files with multiple YAML documents?

Yes. Documents separated by --- are formatted individually and joined with --- separators, which is common for Kubernetes manifests.

Beautify YAML with consistent indentation, expand inline {...} and [...] blocks, optionally sort keys, and catch syntax errors with line numbers. Only need a pass/fail check? Use the YAML validator. Runs 100% in your browser.

YAML input

Formatted YAML

Sort keys

Quote all strings

Valid YAML

1 document parsed without syntax errors.

What the YAML checker catches

Indentation errors such as a key indented deeper than its siblings, or tabs used for indentation.
Duplicate keys in the same mapping (many parsers silently keep the last one; this reports the line).
Unclosed flow collections and quotes like [a, b or "text.
Unknown aliases (*name without a matching &name anchor) and bad multi-document separators.

How formatting works

YAML is parsed using its version directive, or YAML 1.2 by default, then printed in block style with consistent indentation.
The formatter refuses numeric scalars whose spelling it cannot safely preserve. YAML 1.1 and 1.2 can interpret the same scalar differently.
Comments and anchors are retained where possible; review the output and keep the original. Sorting is disabled for files with anchors or aliases.
Custom tags are preserved, but their application-specific meanings cannot be validated here.
Multi-document files (separated by ---) are formatted document by document.
Need JSON instead? Use YAML to JSON or go the other way with JSON to YAML.

YAML Formatter

What the YAML checker catches

How formatting works

FAQ

How do I format YAML online?

Does the YAML formatter keep comments?

Will formatting change my values?

Why can't I quote all strings?

Can it format files with multiple YAML documents?

Is my YAML uploaded?

See also