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SDK 1.0.4181-prerelease, for Runtime 152 (Aug. 3, 2026)

Release notes for Microsoft Edge WebView2 Prerelease SDK, release date: Aug. 3, 2026.

NuGet package for WebView2 SDK 1.0.4181-prerelease

For full API compatibility, this Prerelease version of the WebView2 SDK requires the WebView2 Runtime that ships with Microsoft Edge version 152.0.4181.0 or later; see Preview Runtime 152.0.4181.0 (Aug. 3, 2026).

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.

Diagnostic Monitor API

The DiagnosticMonitor API provides an observation-only logging surface that lets a host application collect detailed diagnostic signals from WebView2. A monitor observes signals from all WebViews, profiles, and the environment through a single DiagnosticReceived event.

The event is for offline analysis or telemetry forwarding; it cannot be intercepted, modified, or deferred.

A host app creates a monitor by calling CoreWebView2Environment.CreateDiagnosticMonitor. A newly created monitor is inert and delivers no events until the app opts in per category by calling SetDiagnosticFilter with a diagnostic category (such as NetworkRequest) and a JSON filter string.

Passing "{}" to SetDiagnosticFilter receives all events in that category. A non-empty JSON object applies field-level matching (such as for filtering network requests) to specific errorCode or httpMethod values.

Calling SetDiagnosticFilter again for the same category replaces the previous filter.

Each DiagnosticReceived event exposes the Category, Scope, Timestamp, and a DetailsAsJson payload whose schema is defined per category with a set of guaranteed fields. The API is JSON-in/JSON-out by design, so new categories and fields can ship without breaking the API contract; consumers must ignore unknown keys.

Releasing or closing the monitor stops all events and clears all filters.

Bug fixes

  • Fixed a WPF crash when changing display topology in composition-controlled apps.

See also

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