Microsoft reports 41% fewer allocations and 25% less time in WinUI code for File Explorer launch, with improvements coming to WinAppSDK 2.x.
Key Takeaways
File Explorer launch benchmarks show 41% fewer allocations, 63% fewer transient allocations, 45% fewer function calls, and 25% less WinUI execution time.
Notepad and File Explorer are the primary benchmarks; improvements are scoped to broadly benefit most apps, not just those two.
Changes land in winui3/main soon; WinAppSDK 2.x backports planned where servicing risk is acceptable.
Some optimizations require opt-in due to breaking changes in control templates or animation-set properties; opt-out defaults may arrive in WinUI 3.0 or 4.0+.
Microsoft frames WinUI 3 as the strategic native Windows framework going forward, with this work tied to a public quality commitment.
Hacker News Comment Review
Commenters are broadly skeptical that isolated WinUI wins translate to perceptible UX improvements; the consensus is that systemic slowness in Windows 11 apps like calc.exe and Photos reflects policy, not just framework limits.
The cross-platform question dominated: several builders said they would not choose WinUI 3 even for Windows-only work, with Windows Forms plus Blazor cited as a practical alternative to modern Windows UI stacks.
Apple’s Finder drew comparison as a counterexample of a fast-hardware, slow-UI product, suggesting the problem is industry-wide and not unique to Microsoft.
Notable Comments
@electroly: Recommends Windows Forms with Blazor over WinUI 3 even for Windows-only desktop apps, dismissing modern Windows UI stacks entirely.
@wiseowise: “nobody gives a shit about doing great technical work unless it aligns with some VPs goals” – frames the announcement as org-incentive-driven, not engineering-driven.
