Explainer1 min readUpdated June 29, 2026

What is XML?

Short answer

XML (Extensible Markup Language) stores structured data in nested, named tags, optionally with attributes. It is verbose but very expressive, and it underpins formats like RSS, SVG, and many office and enterprise documents.

Data in nested tags

XML wraps data in tags you define yourself. Each element has an opening and closing tag, can contain other elements, and can carry attributes for extra detail. The result is a tree that describes both the data and its structure.

<user id="42">
  <name>Ada</name>
  <role>author</role>
</user>

An XML element

Elements vs attributes

Information can live as a child element, like <name>Ada</name>, or as an attribute, like id="42". Attributes suit small, simple metadata, while elements suit richer or repeating content.

Where XML is used

RSS and Atom feeds
SVG vector graphics, which are XML
Office document formats and many configuration files
Enterprise data exchange with schema validation (XSD)

XML vs JSONFor web APIs, JSON is usually lighter and easier. XML still wins where attributes, namespaces, mixed content, or strict schemas matter. See JSON vs XML.

Try it: XML FormatterFormat and indent XML to make it readable, locally in your browser.Open tool

References

Questions

Is HTML the same as XML?

They are related but not the same. Both use tags, but HTML has a fixed vocabulary for web pages and is lenient, while XML lets you define your own tags and is strict about being well-formed.

Is XML obsolete?

No. JSON has replaced it for many web APIs, but XML remains widespread in feeds, SVG, office documents, and enterprise systems with mature schema tooling.

Does this send my data anywhere?

No. Utilumo's developer tools parse and transform input inside the browser tab. Nothing is uploaded, stored, or logged.