hot-reload

Since the September 2026 .NET SDKs (10.0.112, 10.0.401, 11 RC1), dotnet watch rejects browser-refresh WebSockets from unknown origins. Set DOTNET_WATCH_AUTO_RELOAD_WS_ORIGINS to your host name.

A dwds bug in Flutter 3.35 web sent a fake pause on every hot reload. Upgrade to Flutter 3.38+, or switch VS Code back to 'Debug my code' so package frames are skipped.

dotnet run builds your project once and launches it. dotnet watch wraps dotnet run in a file watcher: it relaunches or hot reloads the app every time you save a source file. Here is exactly what each one does, what dotnet watch sets that dotnet run does not, and when to reach for which.

.NET 11 Preview 4 turns on dotnet watch for Android devices, Android emulators, and the iOS Simulator. Edit, save, and the running app updates without a manual rebuild. One csproj gotcha applies to iOS.

Visual Studio 2026 adds HotReloadAutoRestart, a project-level opt-in that restarts the app when a rude edit would otherwise end the debug session. It is especially useful for Razor and Aspire projects.