Learn Blazor by Building a Chrome Extension: Build a Real Browser Extension in C# and WebAssembly — No JavaScript Required, with MudBlazor and Manifest V3 (C#/.NET in Practice Book 5)

You can write web UI in C# alone — you've heard the claim, but you stall on the difference between WASM, Server, and Hybrid. This book clears that fog by building one small Chrome extension, start to finish.

You build QuickMemo: a popup extension that saves, searches, tags, and copies notes. From an empty project to a Manifest V3 extension running in your own browser (Chrome / Edge), you write both the UI and the logic entirely in C#. Blazor WebAssembly's output is a set of static files, no server needed — which fits a browser extension exactly, so you tour Blazor by the shortest path.

What you'll learn - The big picture: WASM / Server / Hybrid, and how Blazor compares to React and Vue

- Blazor fundamentals: Razor components, @bind, DI, @page routing

- Extension basics: Manifest V3, the four execution contexts, chrome.storage

- The heart of the book: the three walls to running the build output as an extension, and how Blazor.BrowserExtension gets past them

- UI: build the popup with MudBlazor's Material Design components

- Implementation: JS interop to chrome.storage.local, plus search, tags, JSON import/export, localization

- Distribution: load in developer mode, debug, publish to the Chrome Web Store / Edge Add-ons

Who this is for - C# developers who know the basics (classes, async/await) and want to try Blazor

- Developers who know the name Blazor but stalled at the first step

- Developers who want to write web UI without adding more JavaScript

C#/.NET in Practice series This book is part of the C#/.NET in Practice series. Its companion Building Desktop Apps with C# and WinUI 3 builds a desktop app in the same C#. Each volume stands on its own.

The finished code is on GitHub.