Microsoft Tests New Tool to Speed up WebView2 Apps on Windows 11

Microsoft plans to improve how complex web apps run on Windows 11 as developers rely more on embedded web interfaces by adding a new API.

What is The Delayed Message Timing API?

Many modern apps use WebView2, which loads web content through the Edge Chromium engine. Users often report that apps like Outlook feel slow, and concerns are rising with the testing of the New Agenda View in Windows 11. WhatsApp also forces a specific WebView2 version on Windows users, which raised additional performance concerns from the community.

Microsoft says today’s web apps run multiple contexts, including windows, iframes and worker threads. These contexts send messages to each other, and delays in that process can slow the entire interface. Developers struggle to locate these bottlenecks without accurate timing data.

Microsoft now tests a new Delayed Message Timing API that shows how long postMessage() calls wait before they reach other web contexts. Developers can measure delays and pinpoint the exact areas that need optimization. This API does not boost performance on its own, but it gives developers the visibility needed to tune their apps.

The feature supports all web apps but also benefits WebView2 apps on Windows 11. Microsoft expects clearer diagnostics to help developers improve responsiveness over time. Users may not see immediate speed improvements, but this sets the groundwork for smoother Outlook, WhatsApp and other WebView2-powered apps.

Via WindowsLatest