diff --git a/microsoft-edge/web-platform/site-impacting-changes.md b/microsoft-edge/web-platform/site-impacting-changes.md index 26d923f14e..213bde7acf 100644 --- a/microsoft-edge/web-platform/site-impacting-changes.md +++ b/microsoft-edge/web-platform/site-impacting-changes.md @@ -5,7 +5,7 @@ author: MSEdgeTeam ms.author: msedgedevrel ms.topic: conceptual ms.service: microsoft-edge -ms.date: 02/27/2025 +ms.date: 03/31/2025 --- # Site compatibility-impacting changes coming to Microsoft Edge @@ -37,6 +37,7 @@ This table lists high-impact changes which the Microsoft Edge team is tracking c | Insecure downloads over HTTP | Future release (TBD) | When a user tries to download potentially dangerous content from an HTTP site, the user will receive a UI warning, such as "Insecure download blocked." The user will still have an option to proceed and download the item. Admins can use the `InsecureContentAllowedForUrls` policy to specify HTTP sites for which the warning will be suppressed. Admins can use the `InsecureDownloadWarnings` feature flag to test the impact of this upcoming feature. | | Deprecate unload event | Future release (TBD) | Introduces a new Permission-Policy to allow creating unload event listeners. The default policy is `allow`, but the default policy will gradually be migrated to `deny`, such that unload handlers stop firing on pages, unless a page explicitly opts in to re-enable them. This change is happening in the Chromium project, on which Microsoft Edge is based. For more information, see [Intent to Deprecate: Deprecate unload event](https://groups.google.com/a/chromium.org/g/blink-dev/c/dvusqw9-IhI/m/SBkm_u1RAQAJ). | | Deprecate `getHostEnvironmentValue` | v137-v141 | Deprecate the non-standards-based, Microsoft Edge-only `window.external.getHostEnvironmentValue()` method, in favor of using the standardized User-Agent Client Hints API to expose browser and platform information. User-Agent Client Hints provide browser and platform information in a more privacy-preserving way. See [Detect Windows 11 and CPU architecture using User-Agent Client Hints](./how-to-detect-win11.md), and [User-Agent Client Hints API](https://developer.mozilla.org/docs/Web/API/User-Agent_Client_Hints_API). | +| HTTPS policy updates | v136-v139 | The `AutomaticHttpsDefault` policy is supported but discouraged in v136, and is planned to be removed in v139. Instead, use the new `HttpsUpgradesEnabled` policy, which is available starting in v136. | | Deprecate `Intl.Locale` getters | v135 | The accessor properties of the `Intl.Locale` object are now deprecated, in favor of the corresponding functions, per specification. See [Deprecate `Intl.Locale` getters](./release-notes/135.md#deprecate-intllocale-getters), in _Microsoft Edge 135 web platform release notes (Apr. 2025)_. | | Remove `navigator.xr.supportsSession` method | v135 | The deprecated `navigator.xr.supportsSession` property is removed from the WebXR API. See [Remove `navigator.xr.supportsSession` method](./release-notes/135.md#remove-navigatorxrsupportssession-method), in _Microsoft Edge 135 web platform release notes (Apr. 2025)_. | | Remove WebGPU limit `maxInterStageShaderComponents` | v135 | The `maxInterStageShaderComponents` limit is now removed. See [Remove WebGPU limit `maxInterStageShaderComponents`](./release-notes/135.md#remove-webgpu-limit-maxinterstageshadercomponents), in _Microsoft Edge 135 web platform release notes (Apr. 2025)_. | diff --git a/microsoft-edge/webview2/concepts/webview-features-flags.md b/microsoft-edge/webview2/concepts/webview-features-flags.md index 7a1c740f1f..b570cd1a7f 100644 --- a/microsoft-edge/webview2/concepts/webview-features-flags.md +++ b/microsoft-edge/webview2/concepts/webview-features-flags.md @@ -6,12 +6,20 @@ ms.author: msedgedevrel ms.topic: conceptual ms.service: microsoft-edge ms.subservice: webview -ms.date: 03/10/2025 +ms.date: 03/28/2025 --- # WebView2 browser flags + One of the ways you can interact with Microsoft Edge WebView2 and impact behavior is by passing browser flags (arguments, or switches) to WebView2. These browser flags are useful for testing forthcoming features, and for diagnosing issues. +For production apps, do not use these flags. During development, if the flag is present, the behavior that's specified below results. + > [!WARNING] > Apps in production shouldn't use WebView2 browser flags, because these flags might be removed or altered at any time, and aren't necessarily supported long-term. @@ -56,8 +64,14 @@ See also Globals: ## Available WebView2 browser flags -The following are some of the flags we've seen used. +The following WebView2 browser flags are available for use during development. + +For production apps, do not use these flags. During development, if the flag is present, the behavior that's specified below results. + | Flag | Description | |---|---| | `accept-lang` | Specifies `Accept-Language` to send to servers and expose to JavaScript via the [Navigator.language](https://developer.mozilla.org/docs/Web/API/Navigator/language) DOM property. The format is `language[-country]`, where `language` is the 2-letter code from ISO-639. | @@ -66,10 +80,10 @@ The following are some of the flags we've seen used. | `allow-run-as-system` | By default, the Edge WebView browser exits if launched as System (launching as System is not recommended). This flag bypasses that check, so that even if the Edge WebView browser is launched as System, the Edge WebView browser doesn't exit. | | `allow-running-insecure-content` | Enables insecure content in Cast Web Runtime. This flag unblocks MSPs that serve content from HTTP sources. | | `auto-open-devtools-for-tabs` | Makes Edge WebView auto-open the DevTools window for each tab. For use by developers and by automation. | -| `AutofillReplaceCachedWebElementsByRendererIds` | If enabled, replaces cached web elements in AutofillAgent and FormTracker by their renderer IDs. | +| `AutofillReplaceCachedWebElementsByRendererIds` | Replaces cached web elements in AutofillAgent and FormTracker by their renderer IDs. | | `autoplay-policy` | Command-line flag name to set the autoplay policy. | | `BlockInsecurePrivateNetworkRequests` | When this feature is enabled, private network requests that are initiated from non-secure contexts in the `public` address space are blocked. | -| `block-new-web-contents` | If `true`, all pop-ups and calls to `window.open` fail. | +| `block-new-web-contents` | Takes a `true` or `false` value. If `true`, makes all pop-ups and calls to `window.open` fail. If `false`, pop-ups and calls to `window.open` are honored. | | `BreakoutBoxPreferCaptureTimestampInVideoFrames` | Reverts the behavior of the `Timestamp` property of the `CoreWebView2Texture` class to match legacy behavior of WebView2 Runtime version 124 and earlier. | | `disable-background-timer-throttling` | Disables task throttling of timer tasks from background pages. | | `disable-domain-action-user-agent-override` | Disables the per-domain User Agent override from the Domain Actions feature. | @@ -95,52 +109,53 @@ The following are some of the flags we've seen used. | `enable-logging` | Enable logging at the error level. | | `force-color-profile` | Force all monitors to be treated as though they have the specified color profile. Valid values: `srgb`, `generic-rgb`. | | `force-device-scale-factor` | Overrides the device scale factor for the Edge WebView browser UI and the contents. | -| `force-fieldtrials` | Can be used to force field trials when testing changes locally. The argument is a list of name/value pairs, separated by forward slashes. If a trial name is prefixed with an asterisk, that trial will start activated. For example, the following argument defines two trials, with the second one activated: `EdgeNow/Enable/*MaterialDesignNTP/Default/`. This option can also be used by the browser process to send the list of trials to a non-browser process, using the same format. | +| `force-fieldtrials` | Can be used to force field trials when testing changes locally. The argument is a list of name/value pairs, separated by forward slashes. If a trial name is prefixed with an asterisk, that trial will start activated. Example: The following argument defines two trials, with the second one activated: `EdgeNow/Enable/*MaterialDesignNTP/Default/`. This option can also be used by the browser process to send the list of trials to a non-browser process, using the same format. | | `force-fieldtrial-params` | Can be used to force parameters of field trials when testing changes locally. The argument is a parameter list of (key, value) pairs, prefixed by an associated (trial, group) pair. For multiple (trial, group) pairs, use a comma separator. | | `force-renderer-accessibility` | Whether to force renderer accessibility to be on, instead of enabling renderer accessibility on-demand when a screen reader is detected. The `disable-renderer-accessibility` flag overrides this flag, if the `disable-renderer-accessibility` flag is present. | | `HardwareMediaKeyHandling` | Enables handling of hardware media keys for controlling media. | | `ignore-certificate-errors` | Ignores certificate-related errors. | | `ignore-gpu-blocklist` | Whether to ignore the GPU blocklist. | | `incognito` | Forces InPrivate (Incognito) mode even if the user data directory is specified by using the `--user-data-dir` flag. | -| `isolate-origins` | Require dedicated processes for a set of origins, specified as a comma-separated list. For example: `--isolate-origins=https://www.foo.com,https://www.bar.com`. | -| `js-flags` | Specifies the flags passed to the JS engine. Available flags: `scavenger_max_new_space_capacity_mb`: Specifies the maximum limit (in MB) for scavenger (minor) garbage collectors in the V8 JavaScript engine. For example:
`--js-flags=--scavenger_max_new_space_capacity_mb=8`
A lower scavenger memory limit reduces memory usage, and increases the frequency of running minor garbage collectors.
A higher scavenger memory limit increases memory usage, and reduces the frequency of running minor garbage collectors. | +| `isolate-origins` | Require dedicated processes for a set of origins, specified as a comma-separated list. Example: `--isolate-origins=https://www.foo.com,https://www.bar.com`. | +| `js-flags` | Specifies the flags passed to the JS engine. Available flags: `scavenger_max_new_space_capacity_mb`: Specifies the maximum limit (in MB) for scavenger (minor) garbage collectors in the V8 JavaScript engine.
A lower scavenger memory limit reduces memory usage, and increases the frequency of running minor garbage collectors.
A higher scavenger memory limit increases memory usage, and reduces the frequency of running minor garbage collectors. Example: `--js-flags=--scavenger_max_new_space_capacity_mb=8`. | | `lang` | The language file that WebView2 want to try to open. Of the form language[-country] where language is the 2-letter code from ISO-639. | | `log-net-log` | Enables saving net log events to a file. If a value is given, that value is used as the directory path and file name. If no value is given, the file is named `netlog.json`, and is placed in the user data directory. | +| `long-animation-frame-timing` | Provides detailed timing for long animation frames, which are frames exceeding the standard 16.67ms duration (60fps). This helps during debugging and performance analysis, to identify and optimize performance bottlenecks for animation-heavy applications. | | `msAbydos` | Enables the "handwriting-to-text" experience. | | `msAbydosGestureSupport` | Allows users to use gestures (such as the scratchout gesture) to delete text by using a pen. Valid only if the `msAbydos` flag is enabled. | | `msAbydosHandwritingAttr` | Whether the "handwriting-to-text" experience is enabled for input elements at the DOM level. Valid only if the `msAbydos` flag is enabled. | | `msAllowAmbientAuthInPrivateWebView2` | This flag is to be used along with the `msSingleSignOnForInPrivateWebView2` browser flag, to enable single sign-on (SSO) with default credential flow or ambient authentication flow. | -| `msEdgeDesignerUI` | Use this flag to disable the Designer Shoreline App. This feature is not supported in WebView2. | -| `msEdgeHubAppDesigner ` | Use this flag to disable the Designer Shoreline App. This feature is not supported in WebView2. | -| `msEdgeDesignerDriverFix ` | Use this flag to disable getting content and automatically showing the Designer feature. This feature is not supported in WebView2. | +| `msEdgeDesignerUI` | Enables the Designer Shoreline App. The Designer Shoreline App is not supported in WebView2. | +| `msEdgeHubAppDesigner ` | Enables the Designer Shoreline App. The Designer Shoreline App is not supported in WebView2. | +| `msEdgeDesignerDriverFix ` | Enables getting content and automatically showing the Designer feature. The Designer feature is not supported in WebView2. | | `msEdgeFluentOverlayScrollbar` | Force-enables Fluent Overlay scrollbars, overriding whatever value `kFluentScrollbar` may hold at the moment. | | `msEdgeDevToolsWdpRemoteDebugging` | Enables remote debugging. See [Remote debugging WebView2 WinUI 2 (UWP) apps](../how-to/remote-debugging.md), [Remotely debug Windows devices](../../devtools-guide-chromium/remote-debugging/windows.md). | -| `msEdgeWebViewApplyWebResourceRequestedFilterForOOPIFs` | If this flag is enabled, the `AddWebResourceRequestedFilter` method (including overloads) will also apply to out-of-process iframes.
.NET: [AddWebResourceRequestedFilter](/dotnet/api/microsoft.web.webview2.core.corewebview2.addwebresourcerequestedfilter)
WinRT: [AddWebResourceRequestedFilter](/microsoft-edge/webview2/reference/winrt/microsoft_web_webview2_core/corewebview2#addwebresourcerequestedfilter)
Win32: [AddWebResourceRequestedFilterWithRequestSourceKinds](/microsoft-edge/webview2/reference/win32/icorewebview2_22#addwebresourcerequestedfilterwithrequestsourcekinds) | +| `msEdgeWebViewApplyWebResourceRequestedFilterForOOPIFs` | Makes the `AddWebResourceRequestedFilter` method (including overloads) also apply to out-of-process iframes.
.NET: [AddWebResourceRequestedFilter](/dotnet/api/microsoft.web.webview2.core.corewebview2.addwebresourcerequestedfilter)
WinRT: [AddWebResourceRequestedFilter](/microsoft-edge/webview2/reference/winrt/microsoft_web_webview2_core/corewebview2#addwebresourcerequestedfilter)
Win32: [AddWebResourceRequestedFilterWithRequestSourceKinds](/microsoft-edge/webview2/reference/win32/icorewebview2_22#addwebresourcerequestedfilterwithrequestsourcekinds) | | `msEnhancedTextContrast` | Improves text contrast enhancement and gamma correction to match the quality and clarity of other native Windows applications. When this flag is used, font rendering respects user ClearType Tuner settings when applying text contrast enhancement and gamma correction. | | `msEnhancedTrackingPreventionEnabled` | Enables native privacy protection features, such as blocking cookies and web requests that reside in domains that are known to be tracking domains. | -| `msFloatyMode` | If `false`, disables the Floaty feature. Use this flag to disable the Floaty feature, because WebView doesn't support browser retention experiments. | -| `msFloatyShouldHonorIndiaHoldout` | If `true`, honors the India holdout group. Use this flag, set to `false`, to disable the Floaty feature that's enabled if the user is part of the India holdout group, because WebView doesn't support browser retention experiments. | +| `msFloatyMode` | Takes a `true` or `false` value. If `true`, enables the Floaty feature. If `false`, disables the Floaty feature. Use this flag to disable the Floaty feature, because WebView doesn't support browser retention experiments. | +| `msFloatyShouldHonorIndiaHoldout` | Takes a `true` or `false` value. If `true`, honors the India holdout group. If `false`, disables the Floaty feature that's enabled if the user is part of the India holdout group, because WebView doesn't support browser retention experiments. | | `msOverlayScrollbarWinStyle` | Whether the users can change between overlay and non-overlay modes for Fluent scrollbars. | | `msPdfEnableAsPreview` | This features enables the PDF viewer to launch with a minimal toolbar and in read-only preview mode. | | `msSingleSignOnForInPrivateWebView2` | This flag enables the single sign-on (SSO) flow for InPrivate (Incognito) sessions of WebView2. Enables browser-based SSO in InPrivate (Incognito) mode. | -| `msSingleSignOnOSForPrimaryAccountIsShared` | If enabled, allows implicit sign-in to Microsoft webpages using any account, by using the information from the primary OS account. | -| `msSmartScreenProtection` | If enabled, SmartScreen protection will be available. | -| `msUseSpellCheckCorrectionsCard` | If enabled, a new corrections card UI is shown when the user clicks a misspelled word. | -| `msWebView2CancelInitialNavigation` | If enabled, cancels the initial navigation in WebView2 to improve startup performance. | -| `msWebView2CodeCache` | If enabled, JavaScript resources that are loaded in a WebView2 app via `SetVirtualHostNameToFolderMapping` or `add_WebResourceRequested` are eligible for bytecode caching, which should speed up the third and subsequent loads. This feature also enables bytecode caching for any other components that use the DevTools network interception mechanism to provide custom responses (see [Custom management of network requests](..\how-to\webresourcerequested.md)). | -| `msWebView2EnableDownloadContentInWebResourceResponseReceived` | If enabled, allow responses of navigations that become downloads to be available in `WebResourceResponseReceived`| -| `msWebView2TextureStream` | If enabled, allows to stream captured or composed video frames to the WebView2 where JavaScript can render or otherwise interact with the frames via W3C standard DOM APIs including the Video element, and MediaStream. | -| `msWebView2EnableDraggableRegions` | If `true`, enables webpages within WebView2 make use of the `app-region: drag\|nodrag` CSS style, which causes elements with that style to behave like a titlebar. Without this flag, the `app-region: drag\|nodrag` CSS style has no effect. | -| `msWebView2CodeCache` | If enabled, JavaScript resources that are loaded in a WebView2 app via `SetVirtualHostNameToFolderMapping` or `add_WebResourceRequested` are eligible for bytecode caching, which should speed up the third and subsequent loads. This feature also enables bytecode caching for any other components that use the DevTools network interception mechanism to provide custom responses. | -| `msWebView2NativeEventDispatch` | If enabled, uses a native mojo connection to dispatch internal events, such as web messages to a renderer process. | -| `msWebView2SimulateMemoryPressureWhenInactive` | If enabled, simulates memory pressure for an inactive WebView. | -| `msWebView2TreatAppSuspendAsDeviceSuspend` | If enabled, when all WebViews are suspended, WebView2 treats the app as if the device is suspended, and pauses all delayed tasks and timers. | +| `msSingleSignOnOSForPrimaryAccountIsShared` | Allows implicit sign-in to Microsoft webpages using any account, by using the information from the primary OS account. | +| `msSmartScreenProtection` | Makes SmartScreen protection available. | +| `msUseSpellCheckCorrectionsCard` | Causes a corrections card UI to be shown when the user clicks a misspelled word. | +| `msWebView2BrowserHitTransparent` | Causes mouse and keyboard events to pass through the WebView2 control to the underlying app, to allow the app to handle these events instead of the WebView2 control handling the events. When this flag is not enabled, the WebView2 control handles mouse and keyboard events; the events don't pass through to the underlying app. This flag allows testing how the app behaves when the WebView2 control doesn't intercept input events, for scenarios where the app needs to handle input events directly. This flag doesn't take a value. This flag might cause the app to crash or freeze.| +| `msWebView2CancelInitialNavigation` | Cancels the initial navigation in WebView2, to improve startup performance. | +| `msWebView2CodeCache` | Makes JavaScript resources that are loaded in a WebView2 app via `SetVirtualHostNameToFolderMapping` or `add_WebResourceRequested` eligible for bytecode caching, which should speed up the third and subsequent loads. This feature also enables bytecode caching for any other components that use the DevTools network interception mechanism to provide custom responses; see [Custom management of network requests](..\how-to\webresourcerequested.md). | +| `msWebView2EnableDownloadContentInWebResourceResponseReceived` | Allows responses of navigations that become downloads to be available in `WebResourceResponseReceived`. | +| `msWebView2TextureStream` | Allows streaming captured or composed video frames to the WebView2 control, where JavaScript can render or otherwise interact with the frames via W3C standard [DOM](https://developer.mozilla.org/docs/Web/API/Document_Object_Model) APIs, including the [Video Embed element](https://developer.mozilla.org/docs/Web/HTML/Element/video) and [MediaStream](https://developer.mozilla.org/docs/Web/API/MediaStream). | +| `msWebView2EnableDraggableRegions` | Takes a `true` or `false` value. If `true`, enables webpages within WebView2 make use of the `app-region: drag\|nodrag` CSS style, which causes elements with that style to behave like a titlebar. If `false`, or without this flag, the `app-region: drag\|nodrag` CSS style has no effect. | +| `msWebView2NativeEventDispatch` | Uses a native mojo connection to dispatch internal events, such as web messages to a renderer process. | +| `msWebView2SimulateMemoryPressureWhenInactive` | Simulates memory pressure for an inactive WebView. | +| `msWebView2TreatAppSuspendAsDeviceSuspend` | When all WebViews are suspended, makes WebView2 treat the app as if the device is suspended, and pauses all delayed tasks and timers. | | `no-proxy-server` | Overrides any other proxy server flags that are passed. | | `net-log-capture-mode` | Sets the granularity of events to capture in the network log. Valid values: `Default`, `IncludeSensitive`, `Everything`. | -| `no-network-profile-warning` | If enabled, the browser warns if the UDF is on a network share. This flag is only supported on Windows; this flag is ignored on other platforms. | +| `no-network-profile-warning` | Causes the browser to warn if the UDF is on a network share. This flag is only supported on Windows; this flag is ignored on other platforms. | | `no-sandbox` | Disables the sandbox for all process types that are normally sandboxed. Meant to be used as a browser-level flag for testing purposes only. | | `no-first-run` | Skips First-Run tasks, regardless of whether it's actually the First Run, and skips displaying the What's New page. This flag is overridden by `kForceFirstRun` (for the First-Run Experience (FRE)) and by `kForceWhatsNew` (for displaying What's New). This flag doesn't drop the First Run sentinel, and thus doesn't prevent the First-Run experience from occurring the next time the Edge WebView browser is launched without this flag. This flag doesn't update the last What's New milestone, so doesn't prevent What's New from being displayed the next time the Edge WebView browser is launched without this flag. | -| `PartitionedCookies` | When enabled, sites can opt-in to having their cookies partitioned by the top-level site by using the `Partitioned` attribute. Partitioned cookies are only sent when the browser is on the same top-level site that it was on when the cookie was set. | +| `PartitionedCookies` | Enables sites to opt-in to having their cookies partitioned by the top-level site by using the `Partitioned` attribute. Partitioned cookies are only sent when the browser is on the same top-level site that it was on when the cookie was set. | | `proxy-auto-detect` | Forces proxy auto-detection. | | `proxy-bypass-list` | A list of hosts for which proxy settings are bypassed; the specified hosts then use direct connections instead. This flag is ignored unless `--proxy-server` is also specified. Multiple hosts can be supplied as a comma-separated list. | | `proxy-server` | A proxy server that overrides system settings. This flag only affects HTTP and HTTPS requests. | @@ -149,17 +164,17 @@ The following are some of the flags we've seen used. | `RendererAppContainer` | Enables Renderer `AppContainer`. | | `Restart` | Indicates that Microsoft Edge WebView2 browser process was restarted (such as after a flag change). Use this flag to ignore the launch when recording the `Launch.Mode2` metric. | | `sdsm-state` | The "Super Duper Secure Mode" state. Valid values: `off`, `basic`, `balanced`, `strict`. | -| `SharedArrayBuffer` | If enabled, indicates that a `SharedArrayBuffer` thread is present. | -| `SpareRendererForSitePerProcess` | If this flag is enabled, the Edge Webview spare renderer process tries to always have a warm spare renderer process running for the most recently requested `BrowserContext`. This feature is only consulted in site-per-process mode. | +| `SharedArrayBuffer` | Indicates that a `SharedArrayBuffer` thread is present. | +| `SpareRendererForSitePerProcess` | Makes the Edge Webview spare renderer process try to always have a warm spare renderer process running for the most recently requested `BrowserContext`. This feature is only consulted in site-per-process mode. | | `ThirdPartyStoragePartitioning` | Enables partitioning of third-party storage, such as `IndexedDB` or `CacheStorage`, by the top-level site, to reduce fingerprinting. | -| `unsafely-treat-insecure-origin-as-secure` | Treats given (insecure) origins as secure origins. Multiple origins can be specified, as a comma-separated list. For the definition of secure contexts, see [Secure Contexts](https://w3c.github.io/webappsec-secure-contexts/), including the section [Is `origin` potentially trustworthy?](https://w3c.github.io/webappsec-secure-contexts/#is-origin-trustworthy). Example: `--unsafely-treat-insecure-origin-as-secure=http://a.test,http://b.test` | +| `unsafely-treat-insecure-origin-as-secure` | Treats given (insecure) origins as secure origins. Multiple origins can be specified, as a comma-separated list. For the definition of secure contexts, see [Secure Contexts](https://w3c.github.io/webappsec-secure-contexts/), including the section [Is `origin` potentially trustworthy?](https://w3c.github.io/webappsec-secure-contexts/#is-origin-trustworthy). Example: `--unsafely-treat-insecure-origin-as-secure=http://a.test,http://b.test`. | | `use-fake-device-for-media-stream` | Uses a fake device for Media Stream to replace an actual camera and microphone. | | `use-fake-ui-for-media-stream` | Bypasses the media stream infobar, by selecting the default device for media streams (such as WebRTC). Works with `--use-fake-device-for-media-stream`. Prefer using `--auto-accept-camera-and-microphone-capture` instead, which doesn't interact with screen capture, such as capturing a browser tab. | | `use-system-proxy-resolver` | Uses WinHttp to resolve proxies instead of using WebView2's normal proxy resolution logic. This flag is only supported in Windows. | | `user-agent` | A string used to override the default user agent with a custom user agent. | | `user-data-migrated` | Indicates that this process is the product of a relaunch following migration of user data. | -| `UseBackgroundNativeThreadPool` | If this is enabled, WebView2 ThreadPoolImpl will use a background ThreadGroup backed by a native thread pool implementation. | -| `UseNativeThreadPool` | If enabled, WebView2 `ThreadPoolImpl` uses a foreground `ThreadGroup` that's backed by a native thread pool implementation. | +| `UseBackgroundNativeThreadPool` | Causes WebView2 ThreadPoolImpl to use a background ThreadGroup backed by a native thread pool implementation. | +| `UseNativeThreadPool` | Causes WebView2 `ThreadPoolImpl` to use a foreground `ThreadGroup` that's backed by a native thread pool implementation. | | `V8Maglev` | Enables the Maglev compiler. This only sets the V8 flag when manually overridden; otherwise, it defers to whatever the V8 default is. | ---