HTML Concepts: Browsing Contexts

Published on September 30, 2022 (↻ October 18, 2024), filed under Development (RSS feed for all categories).

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, as well as 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.

About Me

I’m Jens (long: Jens Oliver Meiert), and I’m a frontend engineering leader and tech author/publisher. I’ve worked as a technical lead for companies like Google and as an engineering manager for companies like Miro, I’m a contributor to several web standards, and I write and review books for O’Reilly and Frontend Dogma.

I love trying things, not only in web development (and engineering management), but also in other areas like philosophy. Here on meiert.com I share some of my experiences and views. (Please be critical, interpret charitably, and give feedback.)