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What is XML?

XML (eXtensible Markup Language) is a markup language for encoding structured data in a text format using nested, custom tags. It supports attributes, namespaces and schema validation (XSD/DTD), and is used for documents, configuration, web feeds (RSS) and enterprise data exchange.

XML wraps data in nested, self-describing tags you define yourself, with optional attributes on elements and namespaces to avoid name clashes. A schema (XSD or DTD) can enforce structure and types.

Once dominant for web services (SOAP) and data interchange, XML is now common for documents (DOCX, SVG), feeds (RSS/Atom) and configuration. JSON has largely replaced it for web APIs.

XML tools

Frequently asked questions

What is the difference between XML and HTML?

HTML has a fixed set of tags for displaying web pages; XML lets you define your own tags to describe data. XML is for storing/transporting data, HTML for presenting it.

Is XML still used?

Yes — for documents, SOAP, RSS/Atom feeds, configuration and enterprise systems needing schema validation, though JSON dominates web APIs.