The browser sandbox wasn't designed to make you safe on the internet. It was designed to stop a very specific thing: a malicious web page from being able to install software on your computer. That's a narrow goal, deliberately so, and understanding what it actually protects against and what sits completely outside its scope changes how you should think about any tool that claims to be "safe because it runs in your browser." The Problem That Triggered the Architecture Before 2008, every major browser ran its entire operation inside a single process. JavaScript execution, page rendering, file handling, network requests: all of it shared the same memory space and, critically, the same access privileges as the user who launched the browser. According to the original Chromium security architecture paper published by researchers at UC Berkeley and Stanford, most web browsers employed a monolithic architecture that combined "the user" and "the web" in...