What it handles
Block mappings and sequences at any depth, inline [a, b] and {k: v} collections, single- and double-quoted strings, literal (|) and folded (>) blocks with their chomping indicators, comments, and multiple documents.
What it refuses, and why that is better
Anchors (&name), aliases (*name) and explicit tags (!!str) are not supported. Rather than silently dropping them — which would hand you JSON that looks complete and is not — the tool stops and tells you which line it met one on.
Tabs are rejected for the same reason: YAML forbids them for indentation, and a file using them is already ambiguous.
Frequently asked questions
Is my config uploaded anywhere?
No. Parsing happens in your browser. Parsing happens in your browser — which matters, because a config file usually carries hostnames and credentials.
It says my file uses anchors. What now?
Expand them where they are used, or run the file through a full YAML implementation first. A converter that quietly ignored them would give you incomplete JSON with no warning.
Why did "yes" become true?
Because in YAML it is. Quote it in the source — "yes" — if you meant the word.
Something wrong with this tool, or an idea for it? Tell us