Overview
- Microsoft detailed Project K2 work to move core parts like the Start menu and File Explorer to WinUI 3 and to speed up the framework itself.
- In a GitHub post, WinUI engineer Beth Pan said the team is focused on launch time and is using File Explorer and Notepad to guide the changes.
- File Explorer tests show about 41% fewer allocations, 63% fewer transient allocations, 45% fewer function calls, and 25% less time spent in WinUI code during launch.
- The updates are set to land in the winui3/main branch with some flowing into WinAppSDK 2.x, and several optimizations will require developers to opt in.
- Microsoft says these tweaks will work with system features like the Low Latency Profile to boost responsiveness, but real-world speed-ups are still being measured.