What this does
Parses YAML and shows it as a collapsible tree of mappings, sequences, and scalars with their types. Aliases are resolved, so a value reused through *name appears at every place it is used.
Multiple documents
When the file contains more than one document, the root of the tree is a list with one entry per document, in order.
Tips
The first two levels start expanded; click a row to open or close it. Scalars show how YAML typed them, for example yes stays a string under YAML 1.2 while true is a boolean and 0o14 is a number. Syntax errors show the line and column.
Privacy
Everything runs in your browser. Your input is never uploaded, stored, or put in the URL.