使用方式

1Paste YAML. Add a YAML document or YAML stream to the input box.

2Check the status. The status bar validates the syntax live and shows the first parser diagnostic when the YAML is invalid.

3Choose indentation. Switch between 2-space and 4-space indentation for the formatted output.

4Copy the result. Copy the formatted YAML once the status says it is valid.

適合誰用

Developers checking Kubernetes, GitHub Actions, Docker Compose or CI configuration before committing it.

DevOps and SRE teams reviewing anchors, aliases and inherited settings in shared YAML files.

Support and QA engineers cleaning up copied snippets while preserving comments for a bug report.

Writers and educators preparing readable YAML examples with consistent indentation.

This formatter uses the YAML 1.2 parser from the yaml package. It parses the document first, reports the first syntax error with a line and column when available, and only then produces a normalized YAML document.

常見問題

Is the YAML formatter free?

Yes. The YAML formatter is free to use, with no sign-up, no download and no usage limit. Paste YAML, read the validation result and copy the formatted output.

Is my YAML uploaded anywhere?

No. Parsing and formatting happen locally in your browser. That makes it suitable for private configuration files, deployment snippets, CI settings and other text you do not want to paste into a server-side tool.

Does it preserve YAML comments and anchors?

Yes, it formats the YAML document tree rather than converting through JSON, so comments, anchors, aliases, merge keys and block strings can stay in the output. Whitespace and quote style may still be normalized by the parser.

Why is my YAML invalid?

Common causes include mixed indentation, a missing colon after a key, an unterminated flow list, tabs used as indentation, or an alias that points to an undefined anchor. The status message shows the parser error and line number when available.

Can it format multiple YAML documents?

Yes. YAML streams that use document markers such as three hyphens are parsed and formatted as multiple documents, and the status panel reports the document count.

Does the formatter change YAML values?

It should not change the parsed meaning of valid YAML, but it may normalize indentation, quotes, collection layout and comment placement. Review the output before replacing a production configuration file.

YAML Formatter 繁體中文