Browser Internals — Free Quiz Course
How browsers actually work: the rendering pipeline, the JavaScript engine, resource loading, storage, the security model, and performance.
5 chapters, 50 questions. Free, no signup. Progress is saved in your browser.
~~~
- Chapter 1: The Rendering PipelineFrom HTML bytes to pixels: parsing, DOM and CSSOM, the render tree, layout, paint, compositing, and what triggers reflows.
- Chapter 2: The JavaScript Engine & Event LoopWhat V8 does with your code: parsing, JIT compilation, the call stack, the event loop, task queues, and garbage collection.
- Chapter 3: Networking & Resource LoadingHow browsers fetch pages: DNS, connections, the preload scanner, script loading with async and defer, and resource priorities.
- Chapter 4: Storage & the Security ModellocalStorage, IndexedDB, cookies, the same-origin policy, site isolation, sandboxing, and how browsers keep sites apart.
- Chapter 5: Performance & DevToolsCore Web Vitals, what blocks the main thread, layout thrashing, memory leaks, and how to find problems with DevTools.
Course completed
You finished every chapter — best score/.
~~~
How it works
Each chapter is a short quiz: one question at a time, with immediate feedback and an explanation after every answer. Wrong answers teach you as much as right ones.
Your progress is stored in your browser (localStorage), so you can leave and come back any time. Nothing leaves your machine, and there is no account or signup.
The questions are based on tutorials published on this site — every chapter links the related posts.