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”

Edge Command Line Arguments

Microsoft Edge offers broad variety of configuration options via Group Policy (for Enterprises), the edge://settings page, the edge://flags page (mostly experimental options), and finally via command-line arguments that are passed to the msedge.exe executable. This list of sources is roughly in order of stability and supportability– earlier choices change less often (and with more notice)Continue reading “Edge Command Line Arguments”

Accessibility (UIA) Troubleshooting

Chromium-based browsers offer a number of accessibility-related features. When you visit about:accessibility, you can see more about the state of these features (similarly, you can find the states in about:histograms/Accessibility.ModeFlag). You can enable features via the Accessibility page, or pass the command line argument –force-renderer-accessibility into the browser. In some cases, you may be surprisedContinue reading “Accessibility (UIA) Troubleshooting”

Determining OS Platform Version

In general, you should not care what Operating System visitors are using to visit your website. If you attempt to be clever, you will often get it wrong and cause problems that are an annoyance for users and a hassle for me to debug. So avoid trying to be nosy/clever if at all possible. ThatContinue reading “Determining OS Platform Version”

window.close() Restrictions

Sometimes, Web Developers are surprised to find that the window.close() API doesn’t always close the browser window. When looking at the Developer Tools console, they’ll see a message like: Scripts may close only the windows that were opened by them. Why Do Browsers Limit close()? Before we dive into what factors govern what happens whenContinue reading “window.close() Restrictions”

Sandboxing vs. Elevated Browsing (As Administrator)

The Web Browser is the most security-critical application on most users’ systems– it accepts untrusted input from servers anywhere in the world, parses that input using dozens to hundreds of parsers, and renders the result locally as fast as it can. For performance reasons, almost all code in almost all browsers is written in memory-unsafeContinue reading “Sandboxing vs. Elevated Browsing (As Administrator)”

Images Keeping You Awake?

A Microsoft Edge user recently complained that her screensaver was no longer activating after the expected delay, and she thought that this might be related to her browser. It was, in a way. To troubleshoot issues where your PC’s screensaver and power-saving options aren’t working correctly, you can use the Power Config command line tool.Continue reading “Images Keeping You Awake?”

Debugging Browsers – Tools and Techniques

Last update: March 29, 2021 Earlier this year, I shared a post on how you can become an expert on web browsers from the comfort of your desk… or anywhere else you have an internet connection. In that post, I mostly covered how to search through the source, review issue reports, and find design documentation.Continue reading “Debugging Browsers – Tools and Techniques”

Browser Memory Limits

Last Update: February 1, 2022 Web browsers are notorious for being memory hogs, but this can be a bit misleading– in most cases, the memory used by the loaded pages accounts for the majority of memory consumption. Unfortunately, some pages are not very good stewards of the system’s memory. One particularly common problem is memoryContinue reading “Browser Memory Limits”

Avoiding Unexpected Navigation

For over twenty years, browsers broadly supported two features that were often convenient but sometimes accidentally invoked, leading to data loss. The first feature was that hitting backspace would send the user back one page in their navigation history. This was convenient for those of us who keep our hands on the keyboard, but couldContinue reading “Avoiding Unexpected Navigation”