Edit

Prerelease SDK 1.0.3415-prerelease, for Runtime 140 (Jul. 14, 2025)

Release notes for Microsoft Edge WebView2 Prerelease SDK, release date: Jul. 14, 2025.

NuGet package for WebView2 SDK 1.0.3415-prerelease

For full API compatibility, this Prerelease version of the WebView2 SDK requires the WebView2 Runtime that ships with Microsoft Edge version 140.0.3415.0 or later; see Runtime 140.0.3485.44 (Sep. 8, 2025).

This SDK version is an exception: it's a later fix for the WebView2 SDK for Runtime 139, and can be conceptually grouped with Release SDK 1.0.3405.78, for Runtime 139 (Aug. 11, 2025).

Detailed contents:

Experimental APIs (Phase 1: Experimental in Prerelease)

The following APIs are in Phase 1: Experimental in Prerelease, and have been added in this Prerelease SDK.

Enable background processing and offline support (WebView2 Worker APIs)

The WebView2 Worker APIs allow host applications to interact with Web Workers to offload tasks from the main thread, improve responsiveness, and support background operations. These Web Workers include Dedicated Workers, Shared Workers, and Service Workers.

These APIs provide:

  • Lifecycle Events: Monitor creation and destruction of workers.
  • Messaging Interfaces: Communicate with workers using PostMessage and WebMessageReceived; specifically:
    • CoreWebView2ServiceWorker.PostWebMessageAsJson
    • CoreWebView2ServiceWorker.PostWebMessageAsString
    • CoreWebView2DedicatedWorker.PostWebMessageAsJson
    • CoreWebView2DedicatedWorker.PostWebMessageAsString
    • CoreWebView2ServiceWorker.WebMessageReceived
    • CoreWebView2DedicatedWorker.WebMessageReceived
    • chrome.webview.postMessage
    • Not: chrome.webview.postMessageWithAdditionalObjects
  • Worker Management: Query and retrieve worker registrations and instances.

Render custom title bars (Window Controls Overlay API)

The Window Controls Overlay API enables developers to create custom title bars by rendering caption buttons (minimize, maximize, restore, close) directly inside the WebView2 window. The Window Controls Overlay appears in the top corner of the WebView, and integrates seamlessly with your app's UI.

Use this API when:

  • You want to replace the default OS title bar with a fully customized in-app title bar.
  • You're working with non-client region features, such as app-region: drag and IsNonClientRegionSupportEnabled.

This API is ideal for apps that require a modern, immersive UI experience.

Promotions to Phase 2 (Stable in Prerelease)

The following APIs have been promoted from Phase 1: Experimental in Prerelease, to Phase 2: Stable in Prerelease, and are included in this Prerelease SDK.

Customize the Find behavior (Find API)

The Find API allows you to programmatically control Find operations, and enables adding the following functionality to your app:

  • Customize Find options, including Find Term, Case Sensitivity, Word Matching, Match Highlighting, and Default UI Suppression.
  • Find text strings and navigate among them within a WebView2 control.
  • Programmatically initiate Find operations, and navigate Find results.
  • Suppress the default Find UI.
  • Track the status of Find operations.

There are known issues with the Find API for PDF documents. When you view a PDF document within a WebView2 control, the Find feature currently only provides the first index and the number of matches found. For example, if the string occurs three times in a PDF, the UI would say 1/3 and would not support programmatically calling Next or Previous.

We're actively investigating these issues, and we encourage you to report any problems you encounter, by using the WebView2Feedback repo.

Previous phase: Customize the Find behavior (Find API) in Prerelease SDK 1.0.3079-prerelease, for Runtime 134 (Jan. 24, 2025).

See also

  • Last updated on