HTML Concepts: Browsing Contexts

Post from September 30, 2022, filed under (feed).

Welcome to another episode of HTML Concepts! Today, browsing contexts—what is that?

The starting point should be the HTML specification (as always—this, and not even MDN, is the source of truth). What does it say?

A browsing context is an environment in which Document objects are presented to the user.

This is cryptic, but the specification goes on to clarify:

A tab or window in a web browser typically contains a browsing context, as does an iframe or frames in a frameset.

This sounds fundamental and indeed, the browsing context is a key concept:

A browsing context is where a user agent displays a document—which often is a tab or window, but can also be an iframe or frame. Every browsing context has its own DOM, origin, navigation and history, and also cookies.

That is, every site or app has a and its own browsing context—and that’s why this is such an important, yet also basic concept.

I’m not sure I made a much more complex subject overly simple, or a simple subject overly complex! Please let me know.

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About Me

Jens Oliver Meiert, on September 30, 2021.

I’m Jens, and I’m an engineering lead and author. I’ve worked as a technical lead for Google, I’m close to W3C and WHATWG, and I write and review books for O’Reilly. I love trying things, sometimes including philosophy, art, and adventure. Here on I share some of my views and experiences.

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