XML
The verbose giant that still runs the world's paperwork.
Where it came from
XML was born in 1996–1998 at the W3C as a simplified subset of SGML, the document format behind HTML. The late 90s bet everything on it: SOAP web services, Office file formats, RSS feeds, Android layouts.
JSON took the web-API crown in the 2010s, but XML never left: office documents (DOCX/XLSX are zipped XML), SVG, RSS/Atom, Maven, Android UI, and half of enterprise B2B still run on it.
How it works
XML is a tree of tagged elements: 〈item attr="value"〉content〈/item〉. Elements nest; attributes carry metadata; text lives between tags. Namespaces (xmlns) prevent collisions between vocabularies.
The eternal conversion question is what to do with attributes vs child elements — UWC maps attributes under a reserved key and keeps the round-trip lossless enough for real-world documents.
Convert XML right here
XML to JSON and back via fast-xml-parser — running fully in your browser.