YAML
Config format that looks like prose.
Where it came from
YAML appeared in 2001, created by Clark Evans, Ingy döt Net and Oren Ben-Kiki. The original backronym was 'Yet Another Markup Language'; later the authors re-branded it 'YAML Ain't Markup Language' to emphasize it describes data, not documents.
Its killer feature was human-friendliness: no braces, minimal quoting, indentation instead of punctuation. That made it the config language of DevOps era — Docker Compose, GitHub Actions, Kubernetes, Ansible all speak YAML.
How it works
Structure comes from indentation: two spaces per level is convention (tabs are forbidden). Key-value pairs are `key: value`; lists use dashes; nested structures just indent further.
Scalars are auto-typed: `true`, `42`, `3.14` become bool/number — this is the source of the famous 'Norway problem', where country code `no` silently becomes boolean false. Quoting a value forces string interpretation.
UWC implements the practical subset of YAML — mappings, sequences, scalars, quoted strings — which covers virtually all real-world configs.
Convert YAML right here
Paste YAML, get JSON or TOML instantly — parsing happens locally, nothing is uploaded.