Anatomy of a Browser: From URL to Pixels
A browser is one of the most complex pieces of software on your computer, juggling network protocols, HTML parsing, CSS layout, GPU rendering, and security—all within milliseconds. This deep dive follows a single navigation from typing a URL to displaying pixels, then traces what happens when you click. It explains the shared architecture behind Chrome, Firefox, and Safari, covering DNS, TLS, HTTP, the DOM, style recalculation, layout, painting, compositing, JavaScript's event loop, process isolation, and more. The goal isn't to memorize internals but to understand the universal problems every browser engine must solve.
A browser is one of the most complicated softwares on your computer. It resolves names, negotiates encrypted connections, speaks several network protocols, executes untrusted programs, calculates two-dimensional geometry, drives the GPU, stores persistent data, exposes accessibility information, and tries to keep mutually hostile websites isolated, all while responding to input within a few milliseconds.