diff --git a/features/broadcast-channel.yml b/features/broadcast-channel.yml
index 2bbef3ae566..5d693b235a5 100644
--- a/features/broadcast-channel.yml
+++ b/features/broadcast-channel.yml
@@ -2,5 +2,6 @@ name: BroadcastChannel
 description: The `BroadcastChannel` API allows you to send messages between same-origin browsing contexts, such as between the same page loaded in multiple tabs.
 spec: https://html.spec.whatwg.org/multipage/web-messaging.html#broadcasting-to-other-browsing-contexts
 caniuse: broadcastchannel
+group: messaging
 status:
   compute_from: api.BroadcastChannel.BroadcastChannel
diff --git a/features/channel-messaging.yml b/features/channel-messaging.yml
new file mode 100644
index 00000000000..2ac05556b0b
--- /dev/null
+++ b/features/channel-messaging.yml
@@ -0,0 +1,16 @@
+name: Channel messaging
+description: "Channel messaging communicates one-to-one between browsing contexts on the same origin, such as between `<iframe>` elements or two documents using a shared worker."
+spec: https://html.spec.whatwg.org/multipage/web-messaging.html#channel-messaging
+caniuse: channel-messaging
+group: messaging
+compat_features:
+  - api.MessageChannel
+  - api.MessageChannel.MessageChannel
+  - api.MessageChannel.port1
+  - api.MessageChannel.port2
+  - api.MessageEvent.ports
+  - api.MessagePort
+  - api.MessagePort.close
+  - api.MessagePort.message_event
+  - api.MessagePort.postMessage
+  - api.MessagePort.start
diff --git a/features/channel-messaging.yml.dist b/features/channel-messaging.yml.dist
new file mode 100644
index 00000000000..6d89e5eb9a4
--- /dev/null
+++ b/features/channel-messaging.yml.dist
@@ -0,0 +1,49 @@
+# Generated from: channel-messaging.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: high
+  baseline_low_date: 2015-09-22
+  baseline_high_date: 2018-03-22
+  support:
+    chrome: "4"
+    chrome_android: "18"
+    edge: "12"
+    firefox: "41"
+    firefox_android: "41"
+    safari: "5"
+    safari_ios: "4.2"
+compat_features:
+  # baseline: high
+  # baseline_low_date: 2015-07-29
+  # baseline_high_date: 2018-01-29
+  # support:
+  #   chrome: "4"
+  #   chrome_android: "18"
+  #   edge: "12"
+  #   firefox: "3"
+  #   firefox_android: "4"
+  #   safari: "4"
+  #   safari_ios: "3.2"
+  - api.MessageEvent.ports
+
+  # baseline: high
+  # baseline_low_date: 2015-09-22
+  # baseline_high_date: 2018-03-22
+  # support:
+  #   chrome: "2"
+  #   chrome_android: "18"
+  #   edge: "12"
+  #   firefox: "41"
+  #   firefox_android: "41"
+  #   safari: "5"
+  #   safari_ios: "4.2"
+  - api.MessageChannel
+  - api.MessageChannel.MessageChannel
+  - api.MessageChannel.port1
+  - api.MessageChannel.port2
+  - api.MessagePort
+  - api.MessagePort.close
+  - api.MessagePort.message_event
+  - api.MessagePort.postMessage
+  - api.MessagePort.start
diff --git a/features/draft/spec/html.yml b/features/draft/spec/html.yml
index 96b98771502..d3a3c44e259 100644
--- a/features/draft/spec/html.yml
+++ b/features/draft/spec/html.yml
@@ -39,9 +39,7 @@ compat_features:
   - api.DataTransferItemList.remove
   - api.DedicatedWorkerGlobalScope
   - api.DedicatedWorkerGlobalScope.close
-  - api.DedicatedWorkerGlobalScope.message_event
   - api.DedicatedWorkerGlobalScope.name
-  - api.DedicatedWorkerGlobalScope.postMessage
   - api.Document
   - api.Document.DOMContentLoaded_event
   - api.Document.activeElement
@@ -98,15 +96,6 @@ compat_features:
   - api.ErrorEvent.filename
   - api.ErrorEvent.lineno
   - api.ErrorEvent.message
-  - api.EventSource
-  - api.EventSource.EventSource
-  - api.EventSource.close
-  - api.EventSource.error_event
-  - api.EventSource.message_event
-  - api.EventSource.open_event
-  - api.EventSource.readyState
-  - api.EventSource.url
-  - api.EventSource.withCredentials
   - api.FileList
   - api.FormDataEvent
   - api.FormDataEvent.FormDataEvent
@@ -244,22 +233,6 @@ compat_features:
   - api.MediaError
   - api.MediaError.code
   - api.MediaError.message
-  - api.MessageChannel
-  - api.MessageChannel.MessageChannel
-  - api.MessageChannel.port1
-  - api.MessageChannel.port2
-  - api.MessageEvent
-  - api.MessageEvent.MessageEvent
-  - api.MessageEvent.data
-  - api.MessageEvent.lastEventId
-  - api.MessageEvent.origin
-  - api.MessageEvent.ports
-  - api.MessageEvent.source
-  - api.MessagePort
-  - api.MessagePort.close
-  - api.MessagePort.message_event
-  - api.MessagePort.postMessage
-  - api.MessagePort.start
   - api.NavigateEvent.canIntercept
   - api.NavigateEvent.hasUAVisualTransition
   - api.NavigateEvent.intercept
@@ -442,7 +415,6 @@ compat_features:
   - api.Window.length
   - api.Window.load_event
   - api.Window.localStorage
-  - api.Window.message_event
   - api.Window.name
   - api.Window.navigator
   - api.Window.offline_event
@@ -456,7 +428,6 @@ compat_features:
   - api.Window.pageswap_event
   - api.Window.parent
   - api.Window.popstate_event
-  - api.Window.postMessage
   - api.Window.prompt
   - api.Window.rejectionhandled_event
   - api.Window.self
@@ -469,9 +440,7 @@ compat_features:
   - api.Worker
   - api.Worker.Worker
   - api.Worker.error_event
-  - api.Worker.message_event
   - api.Worker.messageerror_event
-  - api.Worker.postMessage
   - api.Worker.terminate
   - api.WorkerGlobalScope
   - api.WorkerGlobalScope.error_event
diff --git a/features/draft/spec/html.yml.dist b/features/draft/spec/html.yml.dist
index 67114c748ef..88a565e384e 100644
--- a/features/draft/spec/html.yml.dist
+++ b/features/draft/spec/html.yml.dist
@@ -590,11 +590,6 @@ compat_features:
   - api.Document.activeElement
   - api.Document.hasFocus
   - api.FileList
-  - api.MessageEvent
-  - api.MessageEvent.data
-  - api.MessageEvent.origin
-  - api.MessageEvent.source
-  - api.Window.postMessage
 
   # baseline: high
   # baseline_low_date: 2015-07-29
@@ -608,7 +603,6 @@ compat_features:
   #   safari: "4"
   #   safari_ios: "5"
   - api.Worker
-  - api.Worker.postMessage
   - api.Worker.terminate
 
   # baseline: high
@@ -831,19 +825,6 @@ compat_features:
   #   safari_ios: "4.2"
   - html.global_attributes.draggable
 
-  # baseline: high
-  # baseline_low_date: 2015-07-29
-  # baseline_high_date: 2018-01-29
-  # support:
-  #   chrome: "4"
-  #   chrome_android: "18"
-  #   edge: "12"
-  #   firefox: "3"
-  #   firefox_android: "4"
-  #   safari: "4"
-  #   safari_ios: "3.2"
-  - api.MessageEvent.ports
-
   # baseline: high
   # baseline_low_date: 2015-07-29
   # baseline_high_date: 2018-01-29
@@ -870,11 +851,8 @@ compat_features:
   #   safari_ios: "5"
   - api.DedicatedWorkerGlobalScope
   - api.DedicatedWorkerGlobalScope.close
-  - api.DedicatedWorkerGlobalScope.message_event
-  - api.DedicatedWorkerGlobalScope.postMessage
   - api.Worker.Worker
   - api.Worker.error_event
-  - api.Worker.message_event
   - api.WorkerGlobalScope
   - api.WorkerGlobalScope.error_event
   - api.WorkerGlobalScope.location
@@ -1455,27 +1433,6 @@ compat_features:
   #   safari_ios: "8"
   - api.HTMLImageElement.srcset
 
-  # baseline: high
-  # baseline_low_date: 2015-09-22
-  # baseline_high_date: 2018-03-22
-  # support:
-  #   chrome: "2"
-  #   chrome_android: "18"
-  #   edge: "12"
-  #   firefox: "41"
-  #   firefox_android: "41"
-  #   safari: "5"
-  #   safari_ios: "4.2"
-  - api.MessageChannel
-  - api.MessageChannel.MessageChannel
-  - api.MessageChannel.port1
-  - api.MessageChannel.port2
-  - api.MessagePort
-  - api.MessagePort.close
-  - api.MessagePort.message_event
-  - api.MessagePort.postMessage
-  - api.MessagePort.start
-
   # baseline: high
   # baseline_low_date: 2015-11-12
   # baseline_high_date: 2018-05-12
@@ -1587,19 +1544,6 @@ compat_features:
   #   safari_ios: "6"
   - api.PopStateEvent.PopStateEvent
 
-  # baseline: high
-  # baseline_low_date: 2016-08-02
-  # baseline_high_date: 2019-02-02
-  # support:
-  #   chrome: "16"
-  #   chrome_android: "18"
-  #   edge: "14"
-  #   firefox: "26"
-  #   firefox_android: "26"
-  #   safari: "6"
-  #   safari_ios: "6"
-  - api.MessageEvent.MessageEvent
-
   # baseline: high
   # baseline_low_date: 2016-08-02
   # baseline_high_date: 2019-02-02
@@ -1839,19 +1783,6 @@ compat_features:
   - html.elements.meta.http-equiv.content-security-policy
   - html.elements.meta.http-equiv.content-type
 
-  # baseline: high
-  # baseline_low_date: 2017-08-01
-  # baseline_high_date: 2020-02-01
-  # support:
-  #   chrome: "60"
-  #   chrome_android: "60"
-  #   edge: "12"
-  #   firefox: "9"
-  #   firefox_android: "9"
-  #   safari: "4"
-  #   safari_ios: "4"
-  - api.Window.message_event
-
   # baseline: high
   # baseline_low_date: 2017-10-17
   # baseline_high_date: 2020-04-17
@@ -1975,19 +1906,6 @@ compat_features:
   - api.SVGElement.blur
   - api.SVGElement.focus
 
-  # baseline: high
-  # baseline_low_date: 2018-04-30
-  # baseline_high_date: 2020-10-30
-  # support:
-  #   chrome: "2"
-  #   chrome_android: "18"
-  #   edge: "17"
-  #   firefox: "3"
-  #   firefox_android: "4"
-  #   safari: "4"
-  #   safari_ios: "3.2"
-  - api.MessageEvent.lastEventId
-
   # baseline: high
   # baseline_low_date: 2018-04-30
   # baseline_high_date: 2020-10-30
@@ -2259,25 +2177,6 @@ compat_features:
   - html.elements.iframe.sandbox.allow-same-origin
   - html.elements.iframe.sandbox.allow-scripts
 
-  # baseline: high
-  # baseline_low_date: 2020-01-15
-  # baseline_high_date: 2022-07-15
-  # support:
-  #   chrome: "6"
-  #   chrome_android: "18"
-  #   edge: "79"
-  #   firefox: "6"
-  #   firefox_android: "45"
-  #   safari: "5"
-  #   safari_ios: "5"
-  - api.EventSource
-  - api.EventSource.EventSource
-  - api.EventSource.close
-  - api.EventSource.error_event
-  - api.EventSource.message_event
-  - api.EventSource.open_event
-  - api.EventSource.readyState
-
   # baseline: high
   # baseline_low_date: 2020-01-15
   # baseline_high_date: 2022-07-15
@@ -2317,19 +2216,6 @@ compat_features:
   #   safari_ios: "6"
   - api.PageTransitionEvent.PageTransitionEvent
 
-  # baseline: high
-  # baseline_low_date: 2020-01-15
-  # baseline_high_date: 2022-07-15
-  # support:
-  #   chrome: "18"
-  #   chrome_android: "18"
-  #   edge: "79"
-  #   firefox: "6"
-  #   firefox_android: "45"
-  #   safari: "6"
-  #   safari_ios: "6"
-  - api.EventSource.url
-
   # baseline: high
   # baseline_low_date: 2020-01-15
   # baseline_high_date: 2022-07-15
@@ -2343,19 +2229,6 @@ compat_features:
   #   safari_ios: "7"
   - api.HTMLInputElement.setRangeText
 
-  # baseline: high
-  # baseline_low_date: 2020-01-15
-  # baseline_high_date: 2022-07-15
-  # support:
-  #   chrome: "26"
-  #   chrome_android: "26"
-  #   edge: "79"
-  #   firefox: "6"
-  #   firefox_android: "45"
-  #   safari: "7"
-  #   safari_ios: "7"
-  - api.EventSource.withCredentials
-
   # baseline: high
   # baseline_low_date: 2020-01-15
   # baseline_high_date: 2022-07-15
diff --git a/features/messageerror.yml b/features/messageerror.yml
index c67a0295803..056413958ee 100644
--- a/features/messageerror.yml
+++ b/features/messageerror.yml
@@ -3,3 +3,4 @@ description: The `messageerror` event fires on a target, such as a window or wor
 spec:
   - https://html.spec.whatwg.org/multipage/indices.html#event-messageerror
   - https://w3c.github.io/ServiceWorker/#eventdef-serviceworkerglobalscope-messageerror
+group: messaging
diff --git a/features/postmessage.yml b/features/postmessage.yml
new file mode 100644
index 00000000000..6db84246472
--- /dev/null
+++ b/features/postmessage.yml
@@ -0,0 +1,23 @@
+name: postMessage
+description: "The `postMessage()` global method sends cross-origin messages to windows and workers, including popups and iframes. Also known as cross-document messaging."
+spec: https://html.spec.whatwg.org/multipage/web-messaging.html#web-messaging
+caniuse: x-doc-messaging
+group: messaging
+# Anchor baseline on window support.
+status:
+  compute_from: api.Window.postMessage
+compat_features:
+  # Other features, such as channel messaging and broadcast channels have
+  # `postMessage` methods too, but are not covered by this feature.
+  - api.DedicatedWorkerGlobalScope.postMessage
+  - api.DedicatedWorkerGlobalScope.message_event
+  - api.Window.postMessage
+  - api.Worker.postMessage
+  - api.MessageEvent
+  - api.MessageEvent.MessageEvent
+  - api.MessageEvent.data
+  - api.MessageEvent.lastEventId
+  - api.MessageEvent.origin
+  - api.MessageEvent.source
+  - api.Window.message_event
+  - api.Worker.message_event
diff --git a/features/postmessage.yml.dist b/features/postmessage.yml.dist
new file mode 100644
index 00000000000..7955f75d9e0
--- /dev/null
+++ b/features/postmessage.yml.dist
@@ -0,0 +1,100 @@
+# Generated from: postmessage.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: high
+  baseline_low_date: 2015-07-29
+  baseline_high_date: 2018-01-29
+  support:
+    chrome: "2"
+    chrome_android: "18"
+    edge: "12"
+    firefox: "3"
+    firefox_android: "4"
+    safari: "4"
+    safari_ios: "3.2"
+compat_features:
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: high
+  # baseline_low_date: 2015-07-29
+  # baseline_high_date: 2018-01-29
+  # support:
+  #   chrome: "2"
+  #   chrome_android: "18"
+  #   edge: "12"
+  #   firefox: "3"
+  #   firefox_android: "4"
+  #   safari: "4"
+  #   safari_ios: "3.2"
+  - api.MessageEvent
+  - api.MessageEvent.data
+  - api.MessageEvent.origin
+  - api.MessageEvent.source
+  - api.Window.postMessage
+
+  # baseline: high
+  # baseline_low_date: 2015-07-29
+  # baseline_high_date: 2018-01-29
+  # support:
+  #   chrome: "2"
+  #   chrome_android: "18"
+  #   edge: "12"
+  #   firefox: "3.5"
+  #   firefox_android: "4"
+  #   safari: "4"
+  #   safari_ios: "5"
+  - api.Worker.postMessage
+
+  # baseline: high
+  # baseline_low_date: 2015-07-29
+  # baseline_high_date: 2018-01-29
+  # support:
+  #   chrome: "4"
+  #   chrome_android: "18"
+  #   edge: "12"
+  #   firefox: "3.5"
+  #   firefox_android: "4"
+  #   safari: "4"
+  #   safari_ios: "5"
+  - api.DedicatedWorkerGlobalScope.message_event
+  - api.DedicatedWorkerGlobalScope.postMessage
+  - api.Worker.message_event
+
+  # baseline: high
+  # baseline_low_date: 2016-08-02
+  # baseline_high_date: 2019-02-02
+  # support:
+  #   chrome: "16"
+  #   chrome_android: "18"
+  #   edge: "14"
+  #   firefox: "26"
+  #   firefox_android: "26"
+  #   safari: "6"
+  #   safari_ios: "6"
+  - api.MessageEvent.MessageEvent
+
+  # baseline: high
+  # baseline_low_date: 2017-08-01
+  # baseline_high_date: 2020-02-01
+  # support:
+  #   chrome: "60"
+  #   chrome_android: "60"
+  #   edge: "12"
+  #   firefox: "9"
+  #   firefox_android: "9"
+  #   safari: "4"
+  #   safari_ios: "4"
+  - api.Window.message_event
+
+  # baseline: high
+  # baseline_low_date: 2018-04-30
+  # baseline_high_date: 2020-10-30
+  # support:
+  #   chrome: "2"
+  #   chrome_android: "18"
+  #   edge: "17"
+  #   firefox: "3"
+  #   firefox_android: "4"
+  #   safari: "4"
+  #   safari_ios: "3.2"
+  - api.MessageEvent.lastEventId
diff --git a/features/server-sent-events.yml b/features/server-sent-events.yml
new file mode 100644
index 00000000000..a437d61f447
--- /dev/null
+++ b/features/server-sent-events.yml
@@ -0,0 +1,17 @@
+name: Server-sent events
+description: The `EventSource` API creates a connection to a server and listens to a stream of events sent by the server.
+spec: https://html.spec.whatwg.org/multipage/server-sent-events.html#server-sent-events
+caniuse: eventsource
+group: messaging
+status:
+  compute_from: api.EventSource
+compat_features:
+  - api.EventSource
+  - api.EventSource.EventSource
+  - api.EventSource.close
+  - api.EventSource.error_event
+  - api.EventSource.message_event
+  - api.EventSource.open_event
+  - api.EventSource.readyState
+  - api.EventSource.url
+  - api.EventSource.withCredentials
diff --git a/features/server-sent-events.yml.dist b/features/server-sent-events.yml.dist
new file mode 100644
index 00000000000..5e4d6af80ec
--- /dev/null
+++ b/features/server-sent-events.yml.dist
@@ -0,0 +1,61 @@
+# Generated from: server-sent-events.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: high
+  baseline_low_date: 2020-01-15
+  baseline_high_date: 2022-07-15
+  support:
+    chrome: "6"
+    chrome_android: "18"
+    edge: "79"
+    firefox: "6"
+    firefox_android: "45"
+    safari: "5"
+    safari_ios: "5"
+compat_features:
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: high
+  # baseline_low_date: 2020-01-15
+  # baseline_high_date: 2022-07-15
+  # support:
+  #   chrome: "6"
+  #   chrome_android: "18"
+  #   edge: "79"
+  #   firefox: "6"
+  #   firefox_android: "45"
+  #   safari: "5"
+  #   safari_ios: "5"
+  - api.EventSource
+  - api.EventSource.EventSource
+  - api.EventSource.close
+  - api.EventSource.error_event
+  - api.EventSource.message_event
+  - api.EventSource.open_event
+  - api.EventSource.readyState
+
+  # baseline: high
+  # baseline_low_date: 2020-01-15
+  # baseline_high_date: 2022-07-15
+  # support:
+  #   chrome: "18"
+  #   chrome_android: "18"
+  #   edge: "79"
+  #   firefox: "6"
+  #   firefox_android: "45"
+  #   safari: "6"
+  #   safari_ios: "6"
+  - api.EventSource.url
+
+  # baseline: high
+  # baseline_low_date: 2020-01-15
+  # baseline_high_date: 2022-07-15
+  # support:
+  #   chrome: "26"
+  #   chrome_android: "26"
+  #   edge: "79"
+  #   firefox: "6"
+  #   firefox_android: "45"
+  #   safari: "7"
+  #   safari_ios: "7"
+  - api.EventSource.withCredentials
diff --git a/groups/messaging.yml b/groups/messaging.yml
new file mode 100644
index 00000000000..601ad8a48fb
--- /dev/null
+++ b/groups/messaging.yml
@@ -0,0 +1,4 @@
+# Covers messaging APIs like BroadcastChannel, EventSource and more.
+# The spec calls this group "Communications", but that seems overly
+# general for the web features group.
+name: Messaging