RelNotes: Preview Runtime 155, Stable Runtime 154

microsoft-edge/toc.yml

@@ -1511,7 +1511,10 @@
                 - name: Release notes for the WebView2 Runtime
                   href: ./webview2/release-notes/runtime/index.md
 
-                - name: Preview Runtime 154.0.4258.9 (Sep. 10, 2026)
+                - name: Preview Runtime 155.0.nnnn.nn (Sep. nn, 2026)
+                  href: ./webview2/release-notes/runtime/155.md
+
+                - name: Runtime 154.0.nnnn.nn (Sep. nn, 2026)
                   href: ./webview2/release-notes/runtime/154.md
 
                 - name: Runtime 153.0.4234.32 (Sep. 11, 2026)
@@ -1541,11 +1544,11 @@
                 - name: Runtime 145.0.3800.47 (Feb. 16, 2026)
                   href: ./webview2/release-notes/runtime/145.md
 
-                - name: Runtime 144.0.3719.77 (Jan. 27, 2026)
-                  href: ./webview2/release-notes/runtime/144.md
-
                 - name: Archive
                   items:
+                    - name: Runtime 144.0.3719.77 (Jan. 27, 2026)
+                      href: ./webview2/release-notes/runtime/144.md
+
                     - name: Runtime 143.0.3650.58 (Dec. 8, 2025)
                       href: ./webview2/release-notes/runtime/143.md
 
@@ -1756,6 +1759,12 @@
                 - name: Release notes for WebView2 SDKs
                   href: ./webview2/release-notes/sdk/index.md
 
+                - name: SDK n.n.nnnn-prerelease, for Runtime 155 (Mmm. dd, yyyy)
+                  href: ./webview2/release-notes/sdk/1-0-4999-prerelease.md
+
+                - name: SDK n.n.nnnn.nn, for Runtime 154 (Mmm. dd, yyyy)
+                  href: ./webview2/release-notes/sdk/1-0-4999-nn.md
+
                 - name: SDK 1.0.4255-prerelease, for Runtime 154 (Sep. 11, 2026)
                   href: ./webview2/release-notes/sdk/1-0-4255-prerelease.md
 

microsoft-edge/web-platform/release-notes/154.md

@@ -49,7 +49,7 @@ See [What's new in DevTools (Microsoft Edge 154)](../../devtools/whats-new/154.m
 ## WebView2
 
 See:
-* [Preview Runtime 154.0.4258.9 (Sep. 10, 2026)](../../webview2/release-notes/runtime/154.md)
+* [Runtime 154.0.nnnn.nn (Sep. nn, 2026)](../../webview2/release-notes/runtime/154.md)
 
 
 <!-- ====================================================================== -->

microsoft-edge/webview2/release-notes/runtime/154.md

@@ -1,5 +1,5 @@
 ---
-title: Preview Runtime 154.0.4258.9 (Sep. 10, 2026)
+title: Runtime 154.0.nnnn.nn (Sep. nn, 2026)
 description: Release notes for Microsoft Edge WebView2 Preview Runtime 154.0.4258.9.
 author: MSEdgeTeam
 ms.author: msedgedevrel
@@ -8,7 +8,7 @@ ms.service: microsoft-edge
 ms.subservice: webview
 ms.date: 09/10/2026
 ---
-# Preview Runtime 154.0.4258.9 (Sep. 10, 2026)
+# Runtime 154.0.nnnn.nn (Sep. nn, 2026)
 
 <!-- todo: when this runtime gets released as a stable runtime, follow /release-notes/includes/runtime-template.md:
 remove "preview" from title
@@ -18,16 +18,7 @@ update lead-in sentence
 del See Also link [Prerelease testing using preview channels of Microsoft Edge]
 -->
 
-Release notes for Microsoft Edge WebView2 Preview Runtime, release date: Sep. 10, 2026.
-
-<!-- todo: remove paragraphs when this runtime gets released as a stable runtime -->
-This is a Preview Runtime, for early testing.  Prerelease testing of WebView2 SDKs uses a preview channel of Microsoft Edge (Beta, Dev, or Canary), which includes the WebView2 Preview Runtime.
-
-These release notes are for the WebView2 Preview Runtime, which corresponds to the Beta preview channel of Microsoft Edge.  We recommend testing your app using the Beta preview channel of Microsoft Edge, before these changes are promoted to Stable.  If you want to test even earlier, you can test against Edge Dev or Edge Canary.
-
-See [Prerelease testing using preview channels of Microsoft Edge](../../how-to/prerelease-testing.md).
-
-<!-- / end of remove paragraphs -->
+Release notes for Microsoft Edge WebView2 Runtime, release date: Sep. nn, 2026.
 
 In addition to the following WebView2 Runtime improvements, you can also use the new web platform features from Microsoft Edge 154; see [Microsoft Edge 154 web platform release notes (Sep. 2026)](../../../web-platform/release-notes/154.md).
 

microsoft-edge/webview2/release-notes/runtime/155.md

@@ -0,0 +1,48 @@
+---
+title: Preview Runtime 155.n.nnnn.nn (Mmm. dd, yyyy)
+description: Release notes for Microsoft Edge WebView2 Preview Runtime nnn.n.nnnn.nn.
+author: MSEdgeTeam
+ms.author: msedgedevrel
+ms.topic: article
+ms.service: microsoft-edge
+ms.subservice: webview
+ms.date: 01/01/2026
+---
+# Preview Runtime 155.n.nnnn.nn (Mmm. dd, yyyy)
+<!-- todo: when this runtime gets released as a stable runtime, follow /release-notes/includes/runtime-template.md:
+remove "preview" from title
+update version number
+update date
+update lead-in sentence
+del See Also link [Prerelease testing using preview channels of Microsoft Edge]
+-->
+
+Release notes for Microsoft Edge WebView2 Preview Runtime, release date: Mmm. dd, yyyy.
+
+<!-- todo: remove paragraphs when this runtime gets released as a stable runtime -->
+This is a Preview Runtime, for early testing.  Prerelease testing of WebView2 SDKs uses a preview channel of Microsoft Edge (Beta, Dev, or Canary), which includes the WebView2 Preview Runtime.
+
+These release notes are for the WebView2 Preview Runtime, which corresponds to the Beta preview channel of Microsoft Edge.  We recommend testing your app using the Beta preview channel of Microsoft Edge, before these changes are promoted to Stable.  If you want to test even earlier, you can test against Edge Dev or Edge Canary.
+
+See [Prerelease testing using preview channels of Microsoft Edge](../../how-to/prerelease-testing.md).
+
+<!-- / end of remove paragraphs -->
+
+In addition to the following WebView2 Runtime improvements, you can also use the new web platform features from Microsoft Edge nnn; see [Microsoft Edge nnn web platform release notes (Mmm. yyyy)] (../../../web-platform/release-notes/nnn.md).
+
+
+<!-- ====================================================================== -->
+#### Bug fixes
+
+* Fixed behavior.  ([Issue #] ())
+
+
+<!-- ====================================================================== -->
+## See also
+
+* [SDK n.n.nnnn-prerelease, for Runtime nnn (Mmm. dd, yyyy)] (../sdk/n-n-nnnn-prerelease.md)
+* [Release notes for WebView2](../index.md)
+   * [Release notes for the WebView2 Runtime](./index.md)
+   * [Release notes for WebView2 SDKs](../sdk/index.md)
+* [Prerelease testing using preview channels of Microsoft Edge](../../how-to/prerelease-testing.md)
+* [Microsoft Edge nnn web platform release notes (Mmm. yyyy)] (../../../web-platform/release-notes/nnn.md)

microsoft-edge/webview2/release-notes/runtime/index.md

@@ -15,7 +15,8 @@ list past 10 releases (runtimes)
 in toc.yml, add new relnotes pages, move relnotes pages to archive
 in /webview2/release-notes/runtime/index.md, add new relnotes link, remove earliest relnotes link -->
 Release notes for recent Runtimes:
-* [Preview Runtime 154.0.4258.9 (Sep. 10, 2026)](./154.md)
+* [Preview Runtime 155.n.nnnn.nn (Mmm. dd, yyyy)](./155.md)
+* [Runtime 154.0.nnnn.nn (Sep. nn, 2026)](./154.md)
 * [Runtime 153.0.4234.32 (Sep. 11, 2026)](./153.md)
 * [Runtime 152.0.4191.53 (Aug. 28, 2026)](./152.md)
 * [Runtime 151.0.4129.50 (Aug. 3, 2026)](./151.md)

microsoft-edge/webview2/release-notes/sdk/1-0-4022-49.md

@@ -43,6 +43,9 @@ These APIs provide:
 
 Previous phase: [Enable background processing and offline support (WebView2 Worker APIs)](./1-0-4015-prerelease.md#enable-background-processing-and-offline-support-webview2-worker-apis) in _SDK 1.0.4015-prerelease, for Runtime 149 (May 11, 2026)_.
 
+See also:
+* [Enable background processing and offline support (WebView2 Worker APIs)](../../concepts/overview-features-apis.md?#enable-background-processing-and-offline-support-webview2-worker-apis) in _Overview of WebView2 APIs_.
+
 ##### [.NET/C#](#tab/dotnetcsharp)
 
 <!-- 1 -->

microsoft-edge/webview2/release-notes/sdk/1-0-4255-prerelease.md

@@ -14,7 +14,7 @@ Release notes for Microsoft Edge WebView2 Prerelease SDK, release date: Sep. 3,
 
 [NuGet package for WebView2 SDK 1.0.4255-prerelease](https://www.nuget.org/packages/Microsoft.Web.WebView2/1.0.4255-prerelease)
 
-For full API compatibility, this Prerelease version of the WebView2 SDK requires the WebView2 Runtime that ships with Microsoft Edge version 154.0.4255.0 or later; see [Preview Runtime 154.0.4258.9 (Sep. 10, 2026)](../runtime/154.md).
+For full API compatibility, this Prerelease version of the WebView2 SDK requires the WebView2 Runtime that ships with Microsoft Edge version 154.0.4255.0 or later; see [Runtime 154.0.nnnn.nn (Sep. nn, 2026)](../runtime/154.md).
 
 **Detailed contents:**
 * [Experimental APIs (Phase 1: Experimental in Prerelease)](#experimental-apis-phase-1-experimental-in-prerelease)
@@ -205,7 +205,7 @@ See the [Shared WebView2 Cluster Environment](https://github.com/MicrosoftEdge/W
 <!-- ====================================================================== -->
 ## See also
 
-* [Preview Runtime 154.0.4258.9 (Sep. 10, 2026)](../runtime/154.md)
+* [Runtime 154.0.nnnn.nn (Sep. nn, 2026)](../runtime/154.md)
 * [Release notes for WebView2](../index.md)
    * [Release notes for the WebView2 Runtime](../runtime/index.md)
    * [Release notes for WebView2 SDKs](./index.md)

microsoft-edge/webview2/release-notes/sdk/1-0-4999-nn.md

@@ -0,0 +1,72 @@
+---
+title: SDK n.n.nnnn.nn, for Runtime 154 (Mmm. dd, yyyy)
+description: Release notes for Microsoft Edge WebView2, for Release SDK n.n.nnnn.nn.
+author: MSEdgeTeam
+ms.author: msedgedevrel
+ms.topic: article
+ms.service: microsoft-edge
+ms.subservice: webview
+ms.date: 01/01/2026
+---
+# SDK n.n.nnnn.nn, for Runtime 154 (Mmm. dd, yyyy)
+
+Release notes for Microsoft Edge WebView2 SDK, release date: Mmm. dd, yyyy.
+
+[NuGet package for WebView2 SDK n.n.nnnn.nn] (`https://www.nuget.org/packages/Microsoft.Web.WebView2/n.n.nnnn.nn`)
+
+For full API compatibility, this Release version of the WebView2 SDK requires WebView2 [Runtime nnn.n.nnnn.nn (Mmm. dd, yyyy)] (../runtime/nnn.md) or later.
+
+<!-- if a section is empty, omit the section heading -->
+
+
+<!-- ====================================================================== -->
+## Breaking changes
+
+
+<!-- ------------------------------ -->
+#### heading
+
+
+<!-- ====================================================================== -->
+## General changes
+
+
+<!-- ------------------------------ -->
+#### heading
+
+
+<!-- ====================================================================== -->
+## Promotions to Phase 3 (Stable in Release)
+
+The following APIs have been promoted from Phase 2: Stable in Prerelease, to Phase 3: Stable in Release, and are now included in this Release SDK.
+
+
+<!-- ------------------------------ -->
+#### heading
+
+description
+
+Previous phase: [~] (./~.md#~) in _~_.
+
+##### [.NET/C#](#tab/dotnetcsharp)
+
+##### [WinRT/C#](#tab/winrtcsharp)
+
+##### [Win32/C++](#tab/win32cpp)
+
+---
+
+
+<!-- ====================================================================== -->
+## Bug fixes
+
+* Fixed behavior.  ([Issue #] ())
+
+
+<!-- ====================================================================== -->
+## See also
+
+* [Runtime nnn.n.nnnn.nn (Mmm. dd, yyyy)] (../runtime/nnn.md)
+* [Release notes for WebView2](../index.md)
+   * [Release notes for the WebView2 Runtime](../runtime/index.md)
+   * [Release notes for WebView2 SDKs](./index.md)

microsoft-edge/webview2/release-notes/sdk/1-0-4999-prerelease.md

@@ -0,0 +1,93 @@
+---
+title: SDK n.n.nnnn-prerelease, for Runtime 155 (Mmm. dd, yyyy)
+description: Release notes for Microsoft Edge WebView2 SDK n.n.nnnn-prerelease.
+author: MSEdgeTeam
+ms.author: msedgedevrel
+ms.topic: article
+ms.service: microsoft-edge
+ms.subservice: webview
+ms.date: 01/01/2026
+---
+# SDK n.n.nnnn-prerelease, for Runtime 155 (Mmm. dd, yyyy)
+
+Release notes for Microsoft Edge WebView2 Prerelease SDK, release date: Mmm. dd, yyyy.
+
+[NuGet package for WebView2 SDK n.n.nnnn-prerelease] (`https://www.nuget.org/packages/Microsoft.Web.WebView2/n.n.nnnn-prerelease`)
+
+For full API compatibility, this Prerelease version of the WebView2 SDK requires the WebView2 Runtime that ships with Microsoft Edge version nnn.n.nnnn.n or later; see [Runtime nnn.n.nnnn.nn (Mmm. dd, yyyy)] (../runtime/nnn.md).
+
+<!-- if a section is empty, omit the section heading -->
+
+
+<!-- ====================================================================== -->
+## Breaking changes
+
+
+<!-- ------------------------------ -->
+#### heading
+
+
+<!-- ====================================================================== -->
+## General changes
+
+
+<!-- ------------------------------ -->
+#### heading
+
+
+<!-- ====================================================================== -->
+## 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.
+
+
+<!-- ------------------------------ -->
+#### heading
+
+description
+
+##### [.NET/C#](#tab/dotnetcsharp)
+
+##### [WinRT/C#](#tab/winrtcsharp)
+
+##### [Win32/C++](#tab/win32cpp)
+
+---
+
+
+<!-- ====================================================================== -->
+## 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.
+The following APIs skipped Phase 1: Experimental in Prerelease, and have been directly added to Phase 2: Stable in Prerelease, and are included in this Prerelease SDK.
+
+
+<!-- ------------------------------ -->
+#### heading
+
+description
+
+Previous phase: [~] (./~.md#~) in _~_.
+
+##### [.NET/C#](#tab/dotnetcsharp)
+
+##### [WinRT/C#](#tab/winrtcsharp)
+
+##### [Win32/C++](#tab/win32cpp)
+
+---
+
+
+<!-- ====================================================================== -->
+## Bug fixes
+
+* Fixed behavior.  ([Issue #] ())
+
+
+<!-- ====================================================================== -->
+## See also
+
+* [Runtime nnn.n.nnnn.nn (Mmm. dd, yyyy)] (../runtime/nnn.md)
+* [Release notes for WebView2](../index.md)
+   * [Release notes for the WebView2 Runtime](../runtime/index.md)
+   * [Release notes for WebView2 SDKs](./index.md)

microsoft-edge/webview2/release-notes/sdk/index.md

@@ -15,6 +15,8 @@ list past 10 releases
 in toc.yml, add new relnotes pages, move relnotes pages to archive
 in /webview2/release-notes/sdk/index.md, add new relnotes links, remove earliest relnotes links -->
 Release notes for recent SDKs:
+* [SDK n.n.nnnn-prerelease, for Runtime 155 (Mmm. dd, yyyy)](./1-0-4999-prerelease.md)
+* [SDK n.n.nnnn.nn, for Runtime 154 (Mmm. dd, yyyy)](./1-0-4999-nn.md)
 * [SDK 1.0.4255-prerelease, for Runtime 154 (Sep. 11, 2026)](./1-0-4255-prerelease.md)
 * [SDK 1.0.4191.47, for Runtime 152 (Aug. 28, 2026)](./1-0-4191-47.md)
 * [SDK 1.0.4181-prerelease, for Runtime 152 (Aug. 3, 2026)](./1-0-4181-prerelease.md)