diff --git a/src/renderer/src/App.test.tsx b/src/renderer/src/App.test.tsx
index 61702d9d..2ad1c575 100644
--- a/src/renderer/src/App.test.tsx
+++ b/src/renderer/src/App.test.tsx
@@ -44,6 +44,19 @@ const speechRecognitionMocks = vi.hoisted(() => ({
   startPcmRecording: vi.fn()
 }))
 
+const messageRenderProbe = vi.hoisted(() => vi.fn())
+
+vi.mock('./MarkdownRenderer', async (importOriginal) => {
+  const original = await importOriginal<typeof import('./MarkdownRenderer')>()
+  return {
+    ...original,
+    MarkdownRenderer: (props: { children: string; renderHtml?: boolean }) => {
+      messageRenderProbe(props.children)
+      return <original.MarkdownRenderer {...props} />
+    }
+  }
+})
+
 const lazyRouteMocks = vi.hoisted(() => {
   let pending: Promise<void> | undefined
   let releasePending: (() => void) | undefined
@@ -2527,6 +2540,28 @@ describe('App', () => {
     ).not.toBeInTheDocument()
   })
 
+  it('measures composer height once per input and resizes after sending', async () => {
+    render(<App />)
+    const input = await screen.findByLabelText('向 GoodBuddy 提问')
+    const measureHeight = vi.fn(() =>
+      (input as HTMLTextAreaElement).value ? 300 : 0
+    )
+    Object.defineProperty(input, 'scrollHeight', {
+      configurable: true,
+      get: measureHeight
+    })
+
+    fireEvent.input(input, { target: { value: 'First line\nSecond line' } })
+    expect(measureHeight).toHaveBeenCalledTimes(1)
+    expect(input).toHaveStyle({ height: '220px' })
+
+    measureHeight.mockClear()
+    fireEvent.click(screen.getByLabelText('发送'))
+    await waitFor(() => expect(input).toHaveValue(''))
+    expect(measureHeight).toHaveBeenCalledTimes(1)
+    expect(input).toHaveStyle({ height: '72px' })
+  })
+
   it('shows a red recording state until microphone capture stops', async () => {
     let resolveRecording!: (value: {
       audio: ArrayBuffer
@@ -3325,9 +3360,12 @@ describe('App', () => {
       scrollTop: { configurable: true, writable: true, value: 225 }
     })
     fireEvent.scroll(firstChat)
+    messageRenderProbe.mockClear()
     fireEvent.change(screen.getByLabelText('向 GoodBuddy 提问'), {
       target: { value: '第一段会话草稿' }
     })
+    expect(messageRenderProbe).not.toHaveBeenCalled()
+    expect(firstPane?.querySelectorAll('.message')).toHaveLength(160)
     fireEvent.click(screen.getByLabelText('添加附件'))
     expect(
       await screen.findByText(draftAttachment.name)
@@ -3341,9 +3379,12 @@ describe('App', () => {
     expect(
       screen.queryByText(draftAttachment.name)
     ).not.toBeInTheDocument()
+    messageRenderProbe.mockClear()
     fireEvent.change(screen.getByLabelText('向 GoodBuddy 提问'), {
       target: { value: '第二段会话草稿' }
     })
+    expect(messageRenderProbe).not.toHaveBeenCalled()
+    expect(firstPane?.querySelectorAll('.message')).toHaveLength(160)
     fireEvent.click(
       screen.getByText('第一段长会话').closest('button')!
     )
diff --git a/src/renderer/src/App.tsx b/src/renderer/src/App.tsx
index 95b3aaf9..54ae8a41 100644
--- a/src/renderer/src/App.tsx
+++ b/src/renderer/src/App.tsx
@@ -931,11 +931,23 @@ function ChatHistoryPane({
     0,
     conversation.messages.length - visibleMessageCount
   )
-  const visibleMessages = conversation.messages.slice(
-    visibleMessageStartIndex
+  const visibleMessages = useMemo(
+    () => conversation.messages.slice(visibleMessageStartIndex),
+    [conversation.messages, visibleMessageStartIndex]
   )
   const hiddenMessageCount = visibleMessageStartIndex
 
+  const handleArticleRef = useCallback(
+    (messageId: string, element: HTMLElement | null): void => {
+      if (element) {
+        messageArticleRefs.current.set(messageId, element)
+      } else {
+        messageArticleRefs.current.delete(messageId)
+      }
+    },
+    []
+  )
+
   const saveScrollPosition = useCallback(
     (scrollContainer: HTMLElement): boolean => {
       const distanceFromBottom =
@@ -1068,7 +1080,7 @@ function ChatHistoryPane({
     }
   }, [visibleMessageCount])
 
-  const revealEarlierMessages = (): void => {
+  const revealEarlierMessages = useCallback((): void => {
     const scrollContainer = scrollRef.current
     if (scrollContainer) {
       prependScrollPositionRef.current = {
@@ -1087,7 +1099,12 @@ function ChatHistoryPane({
       conversation.id,
       visibleMessageCount + messageRenderBatchSize
     )
-  }
+  }, [
+    conversation.id,
+    conversation.messages,
+    onVisibleMessageCountChange,
+    visibleMessageCount
+  ])
 
   const scrollToBottom = (): void => {
     const scrollContainer = scrollRef.current
@@ -1156,13 +1173,7 @@ function ChatHistoryPane({
           locale={locale}
           messages={visibleMessages}
           messageStartIndex={visibleMessageStartIndex}
-          onArticleRef={(messageId, element) => {
-            if (element) {
-              messageArticleRefs.current.set(messageId, element)
-            } else {
-              messageArticleRefs.current.delete(messageId)
-            }
-          }}
+          onArticleRef={handleArticleRef}
           onCopyMessage={onCopyMessage}
           onDownloadImage={onDownloadImage}
           onOpenCitationContext={onOpenCitationContext}
@@ -3073,7 +3084,7 @@ function App(): React.JSX.Element {
     assistantTasksRef.current = assistantTasks
   }, [assistantTasks])
 
-  useEffect(() => {
+  useLayoutEffect(() => {
     resizeComposerTextarea(inputRef.current)
   }, [input])
 
@@ -9679,9 +9690,6 @@ function App(): React.JSX.Element {
                 title={t('composer.keyboardHint')}
                 value={input}
                 onChange={(event) => setInput(event.target.value)}
-                onInput={(event) =>
-                  resizeComposerTextarea(event.currentTarget)
-                }
                 onPaste={(event) => {
                   const imageItem = Array.from(
                     event.clipboardData.items
diff --git a/src/renderer/src/ChatTimeline.test.tsx b/src/renderer/src/ChatTimeline.test.tsx
index 1c3a6547..0736d852 100644
--- a/src/renderer/src/ChatTimeline.test.tsx
+++ b/src/renderer/src/ChatTimeline.test.tsx
@@ -182,6 +182,12 @@ describe('ChatTimeline', () => {
     unchangedDetails!.open = true
     markdownRenderProbe.mockClear()
 
+    const mapMessages = vi.spyOn(messages, 'map')
+    rerender(<ChatTimeline {...props} messages={messages} />)
+    expect(mapMessages).not.toHaveBeenCalled()
+    expect(markdownRenderProbe).not.toHaveBeenCalled()
+    mapMessages.mockRestore()
+
     const streamedMessages = messages.map((message, index) =>
       index === messages.length - 1
         ? { ...message, content: `${message.content} delta` }
diff --git a/src/renderer/src/ChatTimeline.tsx b/src/renderer/src/ChatTimeline.tsx
index 65d77670..e05a038e 100644
--- a/src/renderer/src/ChatTimeline.tsx
+++ b/src/renderer/src/ChatTimeline.tsx
@@ -1163,7 +1163,7 @@ type ChatTimelineProps = {
   totalMessageCount: number
 }
 
-export function ChatTimeline({
+export const ChatTimeline = memo(function ChatTimeline({
   artifactById,
   conversationId,
   hiddenMessageCount,
@@ -1230,4 +1230,4 @@ export function ChatTimeline({
       })}
     </div>
   )
-}
+})