YAML formatter

Reindent a YAML document without converting it to JSON. The formatter parses the structure before rewriting it, distinguishing mappings, lists and standalone text. It retains the document representation of comments, anchors and multiline values instead of rebuilding only their resolved values. Use it for versioned configuration or an excerpt you need to share with a team. Your file stays in the browser; processing does not access remote repositories or deployment services.

The parser defaults to YAML 1.2 and honors supported version directives. Once the document is recognized, serialization applies the chosen indentation, with a minimum of two spaces. Lists and mappings are identified syntactically rather than by replacing spaces on every line, which could alter literal string content.

Duplicate keys within a mapping, invalid syntax and multiple documents in one input are rejected. Tabs cannot indent YAML structure, although a tab may belong to a value depending on its syntax. A scalar such as not yaml is valid: YAML is not restricted to key/value pairs.

Formatting operates on the YAML document without expanding aliases into JSON objects. Anchors and comments can therefore remain represented. Large integers retain their spelling instead of passing through rounded JavaScript numbers. Presentation spaces, quotation styles and spacing inside compact collections may be normalized; output is not a byte-for-byte copy.

Success means this parser can read the document, not that your application accepts its settings. It does not load files named in configuration paths or interpret custom tags according to application rules. Older YAML consumers may also apply different typing rules, so check the version expected by your environment.