diff --git a/features/draft/spec/cssom-1.yml b/features/draft/spec/cssom-1.yml
index e76fd1deba6..814028e024d 100644
--- a/features/draft/spec/cssom-1.yml
+++ b/features/draft/spec/cssom-1.yml
@@ -1,10 +1,11 @@
-draft_date: 2025-06-19
+draft_date: 2025-09-01
 name: CSS Object Model (CSSOM)
 description: TODO
 spec: https://drafts.csswg.org/cssom-1/
 compat_features:
   - api.CSSStyleProperties
   - api.CSSStyleProperties.cssFloat
+  - api.Document.adoptedStyleSheets.mutable
 
 # The following features in the spec are already part of web-features:
 # - CSS object model:
diff --git a/features/draft/spec/cssom-1.yml.dist b/features/draft/spec/cssom-1.yml.dist
index 9f6244d904f..d5ea1941e73 100644
--- a/features/draft/spec/cssom-1.yml.dist
+++ b/features/draft/spec/cssom-1.yml.dist
@@ -5,5 +5,20 @@ status:
   baseline: false
   support: {}
 compat_features:
+  # baseline: low
+  # baseline_low_date: 2023-03-27
+  # support:
+  #   chrome: "99"
+  #   chrome_android: "99"
+  #   edge: "99"
+  #   firefox: "101"
+  #   firefox_android: "101"
+  #   safari: "16.4"
+  #   safari_ios: "16.4"
+  - api.Document.adoptedStyleSheets.mutable
+
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: false
+  # support: {}
   - api.CSSStyleProperties
   - api.CSSStyleProperties.cssFloat
diff --git a/features/draft/spec/html.yml b/features/draft/spec/html.yml
index 99c94872cd8..aed62123cca 100644
--- a/features/draft/spec/html.yml
+++ b/features/draft/spec/html.yml
@@ -1,9 +1,9 @@
-draft_date: 2025-08-28
+draft_date: 2025-09-01
 name: HTML
 description: TODO
 spec: https://html.spec.whatwg.org/multipage/
 compat_features:
-  - api.CustomElementRegistry.define.connectedMoveCallback_lifecycle_callback
+  - api.Document.designMode
   - api.Document.featurePolicy
   - api.ElementInternals.shadowRoot
   - api.ErrorEvent
@@ -54,6 +54,7 @@ compat_features:
   - api.HTMLUnknownElement
   - api.ImageData.ImageData.settings_parameter
   - api.ImageData.ImageData.settings_parameter.colorSpace_option
+  - api.ImageData.ImageData.settings_parameter.pixelFormat_option
   - api.ImageData.pixelFormat
   - api.MouseEvent.relatedTarget.drag_events
   - api.NavigateEvent.sourceElement
@@ -97,6 +98,7 @@ compat_features:
   - api.reportError
   - api.setInterval.supports_parameters_for_callback
   - api.setTimeout.supports_parameters_for_callback
+  - html.elements.button.command.request-close
   - html.elements.form.autocomplete.new-password
   - html.elements.form.autocomplete.one-time-code
   - html.elements.form.autocomplete.webauthn
@@ -373,6 +375,8 @@ compat_features:
 # - Customized built-in elements:
 #   - api.CustomElementRegistry.builtin_element_support
 #   - html.global_attributes.is
+# - moveBefore():
+#   - api.CustomElementRegistry.define.connectedMoveCallback_lifecycle_callback
 # - :state():
 #   - api.CustomStateSet
 #   - api.CustomStateSet.@@iterator
@@ -413,7 +417,6 @@ compat_features:
 #   - api.Document.body
 #   - api.Document.currentScript
 #   - api.Document.defaultView
-#   - api.Document.designMode
 #   - api.Document.dir
 #   - api.Document.embeds
 #   - api.Document.forms
diff --git a/features/draft/spec/html.yml.dist b/features/draft/spec/html.yml.dist
index 3453950c0bf..88553a07912 100644
--- a/features/draft/spec/html.yml.dist
+++ b/features/draft/spec/html.yml.dist
@@ -478,6 +478,19 @@ compat_features:
   #   safari_ios: "9.3"
   - html.elements.select.autocomplete
 
+  # baseline: high
+  # baseline_low_date: 2020-07-28
+  # baseline_high_date: 2023-01-28
+  # support:
+  #   chrome: "36"
+  #   chrome_android: "36"
+  #   edge: "12"
+  #   firefox: "69"
+  #   firefox_android: "79"
+  #   safari: "10.1"
+  #   safari_ios: "10.3"
+  - api.Document.designMode
+
   # baseline: high
   # baseline_low_date: 2020-07-28
   # baseline_high_date: 2023-01-28
@@ -869,13 +882,6 @@ compat_features:
   #   edge: "126"
   - api.HTMLImageElement.sizes.auto
 
-  # baseline: false
-  # support:
-  #   chrome: "133"
-  #   chrome_android: "133"
-  #   edge: "133"
-  - api.CustomElementRegistry.define.connectedMoveCallback_lifecycle_callback
-
   # baseline: false
   # support:
   #   chrome: "134"
@@ -895,6 +901,7 @@ compat_features:
   #   chrome: "137"
   #   chrome_android: "137"
   #   edge: "137"
+  - api.ImageData.ImageData.settings_parameter.pixelFormat_option
   - api.ImageData.pixelFormat
 
   # baseline: false
@@ -903,6 +910,7 @@ compat_features:
   #   chrome_android: "139"
   #   edge: "139"
   - api.HTMLButtonElement.command.request-close
+  - html.elements.button.command.request-close
 
   # baseline: false
   # support:
diff --git a/features/draft/spec/selectors-4.yml b/features/draft/spec/selectors-4.yml
index af441304707..7e9cbf80953 100644
--- a/features/draft/spec/selectors-4.yml
+++ b/features/draft/spec/selectors-4.yml
@@ -1,9 +1,8 @@
-draft_date: 2025-08-21
+draft_date: 2025-09-01
 name: Selectors Level 4
 description: TODO
 spec: https://drafts.csswg.org/selectors-4/
 compat_features:
-  - css.selectors.closed
   - css.selectors.heading
   - css.selectors.headingfunction
 
diff --git a/features/draft/spec/selectors-4.yml.dist b/features/draft/spec/selectors-4.yml.dist
index 6945895b344..09af86aa212 100644
--- a/features/draft/spec/selectors-4.yml.dist
+++ b/features/draft/spec/selectors-4.yml.dist
@@ -5,6 +5,5 @@ status:
   baseline: false
   support: {}
 compat_features:
-  - css.selectors.closed
   - css.selectors.heading
   - css.selectors.headingfunction
diff --git a/features/draft/spec/webdriver-bidi.yml b/features/draft/spec/webdriver-bidi.yml
index 856c5611b1c..066ff135feb 100644
--- a/features/draft/spec/webdriver-bidi.yml
+++ b/features/draft/spec/webdriver-bidi.yml
@@ -1,4 +1,4 @@
-draft_date: 2025-08-15
+draft_date: 2025-09-01
 name: WebDriver BiDi
 description: TODO
 spec: https://w3c.github.io/webdriver-bidi/
@@ -13,6 +13,8 @@ compat_features:
   - webdriver.bidi.browser.getUserContexts
   - webdriver.bidi.browser.removeUserContext
   - webdriver.bidi.browser.removeUserContext.userContext_parameter
+  - webdriver.bidi.browser.setClientWindowState
+  - webdriver.bidi.browser.setClientWindowState.clientWindow_parameter
   - webdriver.bidi.browsingContext
   - webdriver.bidi.browsingContext.activate
   - webdriver.bidi.browsingContext.activate.context_parameter
@@ -134,6 +136,10 @@ compat_features:
   - webdriver.bidi.browsingContext.userPromptClosed_event.accepted_parameter
   - webdriver.bidi.browsingContext.userPromptClosed_event.context_parameter
   - webdriver.bidi.browsingContext.userPromptClosed_event.type_parameter
+  - webdriver.bidi.browsingContext.userPromptClosed_event.type_parameter.alert
+  - webdriver.bidi.browsingContext.userPromptClosed_event.type_parameter.beforeunload
+  - webdriver.bidi.browsingContext.userPromptClosed_event.type_parameter.confirm
+  - webdriver.bidi.browsingContext.userPromptClosed_event.type_parameter.prompt
   - webdriver.bidi.browsingContext.userPromptClosed_event.userText_parameter
   - webdriver.bidi.browsingContext.userPromptOpened_event
   - webdriver.bidi.browsingContext.userPromptOpened_event.context_parameter
@@ -141,6 +147,10 @@ compat_features:
   - webdriver.bidi.browsingContext.userPromptOpened_event.handler_parameter
   - webdriver.bidi.browsingContext.userPromptOpened_event.message_parameter
   - webdriver.bidi.browsingContext.userPromptOpened_event.type_parameter
+  - webdriver.bidi.browsingContext.userPromptOpened_event.type_parameter.alert
+  - webdriver.bidi.browsingContext.userPromptOpened_event.type_parameter.beforeunload
+  - webdriver.bidi.browsingContext.userPromptOpened_event.type_parameter.confirm
+  - webdriver.bidi.browsingContext.userPromptOpened_event.type_parameter.prompt
   - webdriver.bidi.emulation
   - webdriver.bidi.emulation.setGeolocationOverride
   - webdriver.bidi.emulation.setGeolocationOverride.contexts_parameter
diff --git a/features/draft/spec/webdriver-bidi.yml.dist b/features/draft/spec/webdriver-bidi.yml.dist
index 53e73f95c12..7429870a578 100644
--- a/features/draft/spec/webdriver-bidi.yml.dist
+++ b/features/draft/spec/webdriver-bidi.yml.dist
@@ -618,6 +618,22 @@ compat_features:
   #   firefox_android: "116"
   - webdriver.bidi.session.end
 
+  # baseline: false
+  # support:
+  #   firefox: "118"
+  #   firefox_android: "118"
+  - webdriver.bidi.browsingContext.userPromptOpened_event.type_parameter.alert
+  - webdriver.bidi.browsingContext.userPromptOpened_event.type_parameter.confirm
+  - webdriver.bidi.browsingContext.userPromptOpened_event.type_parameter.prompt
+
+  # baseline: false
+  # support:
+  #   firefox: "119"
+  #   firefox_android: "119"
+  - webdriver.bidi.browsingContext.userPromptClosed_event.type_parameter.alert
+  - webdriver.bidi.browsingContext.userPromptClosed_event.type_parameter.confirm
+  - webdriver.bidi.browsingContext.userPromptClosed_event.type_parameter.prompt
+
   # baseline: false
   # support:
   #   firefox: "122"
@@ -686,10 +702,14 @@ compat_features:
   # baseline: false
   # support: {}
   - webdriver.bidi.browser.createUserContext.unhandledPromptBehavior_parameter
+  - webdriver.bidi.browser.setClientWindowState
+  - webdriver.bidi.browser.setClientWindowState.clientWindow_parameter
   - webdriver.bidi.browsingContext.historyUpdated_event
   - webdriver.bidi.browsingContext.historyUpdated_event.context_parameter
   - webdriver.bidi.browsingContext.historyUpdated_event.timestamp_parameter
   - webdriver.bidi.browsingContext.historyUpdated_event.url_parameter
+  - webdriver.bidi.browsingContext.userPromptClosed_event.type_parameter.beforeunload
+  - webdriver.bidi.browsingContext.userPromptOpened_event.type_parameter.beforeunload
   - webdriver.bidi.emulation.setScreenOrientationOverride
   - webdriver.bidi.emulation.setScreenOrientationOverride.contexts_parameter
   - webdriver.bidi.emulation.setScreenOrientationOverride.screenOrientation_parameter
diff --git a/features/draft/spec/webdriver2.yml b/features/draft/spec/webdriver2.yml
new file mode 100644
index 00000000000..62300190709
--- /dev/null
+++ b/features/draft/spec/webdriver2.yml
@@ -0,0 +1,65 @@
+draft_date: 2025-09-01
+name: WebDriver
+description: TODO
+spec: https://w3c.github.io/webdriver/
+compat_features:
+  - webdriver.bidi.session.new.capabilities_parameter.capability_matching
+
+# The following features in the spec are already part of web-features:
+# - WebDriver:
+#   - api.Navigator.webdriver
+#   - webdriver.classic.AcceptAlert
+#   - webdriver.classic.AddCookie
+#   - webdriver.classic.Back
+#   - webdriver.classic.CloseWindow
+#   - webdriver.classic.DeleteAllCookies
+#   - webdriver.classic.DeleteCookie
+#   - webdriver.classic.DeleteSession
+#   - webdriver.classic.DismissAlert
+#   - webdriver.classic.ElementClear
+#   - webdriver.classic.ElementClick
+#   - webdriver.classic.ElementSendKeys
+#   - webdriver.classic.ExecuteAsyncScript
+#   - webdriver.classic.ExecuteScript
+#   - webdriver.classic.FindElement
+#   - webdriver.classic.FindElementFromElement
+#   - webdriver.classic.FindElements
+#   - webdriver.classic.FindElementsFromElement
+#   - webdriver.classic.Forward
+#   - webdriver.classic.FullscreenWindow
+#   - webdriver.classic.GetActiveElement
+#   - webdriver.classic.GetAlertText
+#   - webdriver.classic.GetAllCookies
+#   - webdriver.classic.GetCurrentURL
+#   - webdriver.classic.GetElementAttribute
+#   - webdriver.classic.GetElementCSSValue
+#   - webdriver.classic.GetElementProperty
+#   - webdriver.classic.GetElementRect
+#   - webdriver.classic.GetElementTagName
+#   - webdriver.classic.GetElementText
+#   - webdriver.classic.GetNamedCookie
+#   - webdriver.classic.GetPageSource
+#   - webdriver.classic.GetTimeouts
+#   - webdriver.classic.GetTitle
+#   - webdriver.classic.GetWindowHandle
+#   - webdriver.classic.GetWindowHandles
+#   - webdriver.classic.GetWindowRect
+#   - webdriver.classic.IsElementEnabled
+#   - webdriver.classic.IsElementSelected
+#   - webdriver.classic.MaximizeWindow
+#   - webdriver.classic.MinimizeWindow
+#   - webdriver.classic.NavigateTo
+#   - webdriver.classic.NewSession
+#   - webdriver.classic.NewWindow
+#   - webdriver.classic.PerformActions
+#   - webdriver.classic.Refresh
+#   - webdriver.classic.ReleaseActions
+#   - webdriver.classic.SendAlertText
+#   - webdriver.classic.SetTimeouts
+#   - webdriver.classic.SetWindowRect
+#   - webdriver.classic.Status
+#   - webdriver.classic.SwitchToFrame
+#   - webdriver.classic.SwitchToParentFrame
+#   - webdriver.classic.SwitchToWindow
+#   - webdriver.classic.TakeElementScreenshot
+#   - webdriver.classic.TakeScreenshot
diff --git a/features/draft/spec/webdriver2.yml.dist b/features/draft/spec/webdriver2.yml.dist
new file mode 100644
index 00000000000..2e0bca60648
--- /dev/null
+++ b/features/draft/spec/webdriver2.yml.dist
@@ -0,0 +1,11 @@
+# Generated from: webdriver2.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: false
+  support:
+    chrome: "139"
+    chrome_android: "139"
+    edge: "139"
+compat_features:
+  - webdriver.bidi.session.new.capabilities_parameter.capability_matching
diff --git a/features/draft/spec/webgpu.yml b/features/draft/spec/webgpu.yml
index 1175e675210..f1498a5be6d 100644
--- a/features/draft/spec/webgpu.yml
+++ b/features/draft/spec/webgpu.yml
@@ -1,4 +1,4 @@
-draft_date: 2025-07-03
+draft_date: 2025-09-01
 name: WebGPU
 description: TODO
 spec: https://gpuweb.github.io/gpuweb/
@@ -7,6 +7,7 @@ compat_features:
   - api.GPUAdapterInfo.isFallbackAdapter
   - api.GPUCommandEncoder.copyBufferToBuffer.offset_and_size_parameter_optional
   - api.GPUDevice.createBindGroup.descriptor_entries_option_accepts_GPUTextureView_resource
+  - api.GPUSupportedFeatures.feature_core-features-and-limits
   - api.GPUSupportedFeatures.feature_subgroups
 
 # The following features in the spec are already part of web-features:
diff --git a/features/draft/spec/webgpu.yml.dist b/features/draft/spec/webgpu.yml.dist
index 3db2d4ecd09..64d2d683d59 100644
--- a/features/draft/spec/webgpu.yml.dist
+++ b/features/draft/spec/webgpu.yml.dist
@@ -4,9 +4,9 @@
 status:
   baseline: false
   support:
-    chrome: "137"
-    chrome_android: "137"
-    edge: "137"
+    chrome: "139"
+    chrome_android: "139"
+    edge: "139"
 compat_features:
   # baseline: false
   # support:
@@ -29,7 +29,6 @@ compat_features:
   #   edge: "136"
   - api.GPUAdapterInfo.isFallbackAdapter
 
-  # ⬇️ Same status as overall feature ⬇️
   # baseline: false
   # support:
   #   chrome: "137"
@@ -37,3 +36,11 @@ compat_features:
   #   edge: "137"
   - api.GPUCommandEncoder.copyBufferToBuffer.offset_and_size_parameter_optional
   - api.GPUDevice.createBindGroup.descriptor_entries_option_accepts_GPUTextureView_resource
+
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: false
+  # support:
+  #   chrome: "139"
+  #   chrome_android: "139"
+  #   edge: "139"
+  - api.GPUSupportedFeatures.feature_core-features-and-limits
diff --git a/features/draft/spec/webrtc-encoded-transform.yml b/features/draft/spec/webrtc-encoded-transform.yml
new file mode 100644
index 00000000000..39d425ba936
--- /dev/null
+++ b/features/draft/spec/webrtc-encoded-transform.yml
@@ -0,0 +1,31 @@
+draft_date: 2025-09-01
+name: WebRTC Encoded Transform
+description: TODO
+spec: https://w3c.github.io/webrtc-encoded-transform/
+compat_features:
+  - api.RTCEncodedAudioFrame.getMetadata.return_object_property_audioLevel
+
+# The following features in the spec are already part of web-features:
+# - WebRTC encoded transform:
+#   - api.DedicatedWorkerGlobalScope.rtctransform_event
+#   - api.RTCEncodedAudioFrame
+#   - api.RTCEncodedAudioFrame.RTCEncodedAudioFrame
+#   - api.RTCEncodedAudioFrame.data
+#   - api.RTCEncodedAudioFrame.getMetadata
+#   - api.RTCEncodedVideoFrame
+#   - api.RTCEncodedVideoFrame.RTCEncodedVideoFrame
+#   - api.RTCEncodedVideoFrame.data
+#   - api.RTCEncodedVideoFrame.getMetadata
+#   - api.RTCEncodedVideoFrame.type
+#   - api.RTCRtpReceiver.transform
+#   - api.RTCRtpScriptTransform
+#   - api.RTCRtpScriptTransform.RTCRtpScriptTransform
+#   - api.RTCRtpScriptTransformer
+#   - api.RTCRtpScriptTransformer.generateKeyFrame
+#   - api.RTCRtpScriptTransformer.options
+#   - api.RTCRtpScriptTransformer.readable
+#   - api.RTCRtpScriptTransformer.sendKeyFrameRequest
+#   - api.RTCRtpScriptTransformer.writable
+#   - api.RTCRtpSender.transform
+#   - api.RTCTransformEvent
+#   - api.RTCTransformEvent.transformer
diff --git a/features/draft/spec/webrtc-encoded-transform.yml.dist b/features/draft/spec/webrtc-encoded-transform.yml.dist
new file mode 100644
index 00000000000..415d9849621
--- /dev/null
+++ b/features/draft/spec/webrtc-encoded-transform.yml.dist
@@ -0,0 +1,11 @@
+# Generated from: webrtc-encoded-transform.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: false
+  support:
+    chrome: "139"
+    chrome_android: "139"
+    edge: "139"
+compat_features:
+  - api.RTCEncodedAudioFrame.getMetadata.return_object_property_audioLevel