Microsoft is actively working to make complex web applications run faster within Windows 11. The company is embracing its WebView2 technology and introducing a new diagnostic tool to help developers improve performance. This effort aims to enhance the user experience for applications like Outlook and others that embed web content directly into the operating system.
Understanding WebView2's Role
WebView2 is Microsoft's embedded web control, built on the same Chromium engine that powers the Microsoft Edge browser. It allows developers to integrate web technologies such as HTML, CSS, and JavaScript directly into native Windows applications. This essentially means a lightweight web browser engine operates inside a desktop application, rather than opening a full browser window.[windowsforum+3]
Microsoft adopted WebView2 as a strategic move to modernize how web content appears in Windows. It replaces older Internet Explorer-based engines and standardizes on Chromium for web rendering, both in the browser and within applications. This approach provides a consistent user experience across Windows 10 and Windows 11, allows developers to reuse web code, and benefits from continuous security updates.[windowsforum+3]
Today, many core Windows 11 features and first-party applications already rely on WebView2. Examples include the Widgets board, the Notification Center's Agenda view, and popular communication tools like Outlook, WhatsApp, and Microsoft Teams. WebView2 also powers Entra ID app sign-ins, enhancing security and consistency across authentication experiences.[windowslatest+6]
Addressing Performance Challenges
Despite the benefits of WebView2, some web-based applications in Windows 11 have faced criticism for high resource usage and perceived slowness. Reports indicate that apps like the new WhatsApp and Microsoft Teams, which utilize WebView2, can consume significant amounts of RAM and sometimes feel less responsive than their native counterparts. For instance, the new WhatsApp app for Windows has been observed to use around 300 MB of RAM before login and can jump to 1.2 GB with active use, leading to noticeable delays and a "heaviness" in the user interface.[windowslatest+1]
These performance issues stem from the nature of embedding a full Chromium runtime. Even though WebView2 aims to be more efficient than frameworks like Electron by using the existing Edge installation, web apps still operate with complex architectures. Each feature or UI element can generate multiple processes due to modern browser security standards, leading to increased memory and CPU demands. Developers have also noted initial delays, sometimes up to 15 seconds, when a WebView2 instance first initializes. High CPU usage is another reported concern for some users.[windowslatest+2]
Microsoft acknowledges that complex applications often rely on intricate architectures involving multiple windows, iframes, or worker threads. The company's goal is not to discourage web apps but to make them perform better within Windows 11.[windowslatest+1]
Microsoft's New Diagnostic Approach
To tackle these performance hurdles, Microsoft is testing a new tool called "Delayed Message Timing." This new API is a diagnostic feature designed to help developers identify and fix performance bottlenecks in web applications. It is not a magical solution to instantly speed up apps. Instead, it provides crucial insights into where an application spends its time.[windowslatest]
The "Delayed Message Timing" API allows developers to measure the time taken when a web app uses the `postMessage()` function. Web apps use `postMessage()` to communicate between different contexts, such as separate windows, iframes, or web workers. By reporting these timings through Performance APIs, the tool helps developers understand specific delays that might be causing an application to feel slow or "stuck".[windowslatest+2]
Microsoft is already using this new API internally to detect performance issues in its own applications, such as Outlook. Future releases of Outlook could see speed improvements as a direct result of insights gained from this diagnostic tool. While the API is particularly helpful for WebView2-based apps, Microsoft intends for the proposal to benefit all web applications, offering a broader impact on web performance within Windows.[windowslatest+2]
Broader Impact for Developers and Users
The continued embrace of WebView2 and the introduction of advanced diagnostic tools underscore Microsoft's commitment to a hybrid app development model. This model combines the broad reach and rapid innovation of web platforms with the power and capabilities of native Windows features. For developers, WebView2 simplifies development by allowing them to leverage the vast web ecosystem, including libraries and tooling, and to reuse code across different platforms. It also reduces the burden of distributing the WebView2 runtime, as it is now included as part of Windows 11 and has been rolled out to many Windows 10 consumer devices.[learn+3]
The platform also supports modern web technologies like React and Fluent UI, making it easier for developers to build consistent and secure interfaces. For users, this means more applications will benefit from up-to-date security patches and compatibility improvements delivered automatically through the evergreen WebView2 runtime. The transition also supports advanced authentication features like passwordless sign-in and passkeys, improving overall security for app logins.[neowin+5]
By investing in tools like "Delayed Message Timing," Microsoft aims to ensure that the integration of web content in Windows 11 delivers not only flexibility and modern features but also the smooth and responsive performance users expect from native applications. This ongoing effort seeks to balance the convenience of web development with a high-quality user experience.




