diff --git a/changelog.d/7691.bugfix b/changelog.d/7691.bugfix
new file mode 100644
index 00000000000..02988191434
--- /dev/null
+++ b/changelog.d/7691.bugfix
@@ -0,0 +1 @@
+Rich Text Editor: improve performance when entering reply/edit/quote mode.
diff --git a/vector/src/main/java/im/vector/app/features/home/room/detail/composer/MessageComposerFragment.kt b/vector/src/main/java/im/vector/app/features/home/room/detail/composer/MessageComposerFragment.kt
index bf9e0ae7260..d56ea8b7339 100644
--- a/vector/src/main/java/im/vector/app/features/home/room/detail/composer/MessageComposerFragment.kt
+++ b/vector/src/main/java/im/vector/app/features/home/room/detail/composer/MessageComposerFragment.kt
@@ -285,7 +285,7 @@ class MessageComposerFragment : VectorBaseFragment<FragmentComposerBinding>(), A
                         else -> return
                     }
 
-                    (composer as? RichTextComposerLayout)?.setFullScreen(setFullScreen)
+                    (composer as? RichTextComposerLayout)?.setFullScreen(setFullScreen, true)
 
                     messageComposerViewModel.handle(MessageComposerAction.SetFullScreen(setFullScreen))
                 }
diff --git a/vector/src/main/java/im/vector/app/features/home/room/detail/composer/MessageComposerMode.kt b/vector/src/main/java/im/vector/app/features/home/room/detail/composer/MessageComposerMode.kt
index a401f04bf5c..89cb1486393 100644
--- a/vector/src/main/java/im/vector/app/features/home/room/detail/composer/MessageComposerMode.kt
+++ b/vector/src/main/java/im/vector/app/features/home/room/detail/composer/MessageComposerMode.kt
@@ -23,6 +23,6 @@ sealed interface MessageComposerMode {
 
     sealed class Special(open val event: TimelineEvent, open val defaultContent: CharSequence) : MessageComposerMode
     data class Edit(override val event: TimelineEvent, override val defaultContent: CharSequence) : Special(event, defaultContent)
-    class Quote(override val event: TimelineEvent, override val defaultContent: CharSequence) : Special(event, defaultContent)
-    class Reply(override val event: TimelineEvent, override val defaultContent: CharSequence) : Special(event, defaultContent)
+    data class Quote(override val event: TimelineEvent, override val defaultContent: CharSequence) : Special(event, defaultContent)
+    data class Reply(override val event: TimelineEvent, override val defaultContent: CharSequence) : Special(event, defaultContent)
 }
diff --git a/vector/src/main/java/im/vector/app/features/home/room/detail/composer/RichTextComposerLayout.kt b/vector/src/main/java/im/vector/app/features/home/room/detail/composer/RichTextComposerLayout.kt
index 16234c37661..d69fe8edeb9 100644
--- a/vector/src/main/java/im/vector/app/features/home/room/detail/composer/RichTextComposerLayout.kt
+++ b/vector/src/main/java/im/vector/app/features/home/room/detail/composer/RichTextComposerLayout.kt
@@ -66,6 +66,7 @@ internal class RichTextComposerLayout @JvmOverloads constructor(
     // There is no need to persist these values since they're always updated by the parent fragment
     private var isFullScreen = false
     private var hasRelatedMessage = false
+    private var composerMode: MessageComposerMode? = null
 
     var isTextFormattingEnabled = true
         set(value) {
@@ -114,9 +115,15 @@ internal class RichTextComposerLayout @JvmOverloads constructor(
 
     private val dimensionConverter = DimensionConverter(resources)
 
-    fun setFullScreen(isFullScreen: Boolean) {
+    fun setFullScreen(isFullScreen: Boolean, animated: Boolean) {
+        if (!animated && views.composerLayout.layoutParams != null) {
+            views.composerLayout.updateLayoutParams<ViewGroup.LayoutParams> {
+                height =
+                        if (isFullScreen) ViewGroup.LayoutParams.MATCH_PARENT else ViewGroup.LayoutParams.WRAP_CONTENT
+            }
+        }
         editText.updateLayoutParams<ViewGroup.LayoutParams> {
-            height = if (isFullScreen) 0 else ViewGroup.LayoutParams.WRAP_CONTENT
+            height = if (isFullScreen) ViewGroup.LayoutParams.MATCH_PARENT else ViewGroup.LayoutParams.WRAP_CONTENT
         }
 
         updateTextFieldBorder(isFullScreen)
@@ -371,7 +378,11 @@ internal class RichTextComposerLayout @JvmOverloads constructor(
     override fun renderComposerMode(mode: MessageComposerMode) {
         if (mode is MessageComposerMode.Special) {
             views.composerModeGroup.isVisible = true
-            replaceFormattedContent(mode.defaultContent)
+            if (isTextFormattingEnabled) {
+                replaceFormattedContent(mode.defaultContent)
+            } else {
+                views.plainTextComposerEditText.setText(mode.defaultContent)
+            }
             hasRelatedMessage = true
             editText.showKeyboard(andRequestFocus = true)
         } else {
@@ -383,10 +394,14 @@ internal class RichTextComposerLayout @JvmOverloads constructor(
                     views.plainTextComposerEditText.setText(text)
                 }
             }
-            views.sendButton.contentDescription = resources.getString(R.string.action_send)
             hasRelatedMessage = false
         }
 
+        updateTextFieldBorder(isFullScreen)
+
+        if (this.composerMode == mode) return
+        this.composerMode = mode
+
         views.sendButton.apply {
             if (mode is MessageComposerMode.Edit) {
                 contentDescription = resources.getString(R.string.action_save)
@@ -397,8 +412,6 @@ internal class RichTextComposerLayout @JvmOverloads constructor(
             }
         }
 
-        updateTextFieldBorder(isFullScreen)
-
         when (mode) {
             is MessageComposerMode.Edit -> {
                 views.composerModeTitleView.setText(R.string.editing)