Chromium Internals: PAK Files

Web browsers are made up of much more than the native code (mostly compiled C++) that makes up their .exe and .dll files. A significant portion of the browser’s functionality (and bulk) is what we’d call “resources”, which include things like: Images (at two resolutions, regular and “high-DPI”) Localized UI Strings HTML, JavaScript, and CSSContinue reading “Chromium Internals: PAK Files”

Smarter Defaults by Paying Attention

As a part of every page load, browsers have to make dozens, hundreds, or even thousands of decisions of varying levels of importance: should a particular API be available? Should a resource load be permitted? Should script be allowed to run? Should video be allowed to start playing automatically? Should cookies or credentials be sentContinue reading “Smarter Defaults by Paying Attention”

MHTML in Chromium

The MHTML file format (aka “Webpage, single file”) allows a single file to contain the multiple resources that are used to load a webpage (script, css, images, etc). Edge (Chromium) has an option to use the format when saving the current page via Ctrl+S or the Save page as… menu command: … but the browser’sContinue reading “MHTML in Chromium”

Debugging Compatibility in Edge

Background By moving from our old codebase to Chromium, the Microsoft Edge team significantly modernized our codebase and improved our compatibility with websites. As we now share the vast majority of our web platform code with the market-leading browser, it’s rare to find websites that behave differently in Edge when compared to Chrome, Brave, Opera,Continue reading “Debugging Compatibility in Edge”

Recognizing Edge Windows

Yesterday, we had a customer reach out to us for help on an issue they’d encountered while writing code to interact with Microsoft Edge windows. Their script enumerated every window in the system, looking for those with Microsoft Edge in the titlebar. They were surprised to discover that the script didn’t recognize any of theirContinue reading “Recognizing Edge Windows”