diff --git a/web/src/lib/clipboard.test.ts b/web/src/lib/clipboard.test.ts
new file mode 100644
index 00000000..2a28276c
--- /dev/null
+++ b/web/src/lib/clipboard.test.ts
@@ -0,0 +1,56 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { safeCopyToClipboard } from './clipboard'
+
+describe('safeCopyToClipboard', () => {
+    beforeEach(() => {
+        vi.restoreAllMocks()
+        Object.defineProperty(document, 'execCommand', {
+            configurable: true,
+            writable: true,
+            value: vi.fn(() => false)
+        })
+    })
+
+    it('uses navigator clipboard writeText when available', async () => {
+        const writeText = vi.fn(async () => {})
+        Object.defineProperty(navigator, 'clipboard', {
+            configurable: true,
+            value: { writeText }
+        })
+        const execCommand = vi.mocked(document.execCommand)
+        execCommand.mockReturnValue(true)
+
+        await safeCopyToClipboard('hello')
+
+        expect(writeText).toHaveBeenCalledWith('hello')
+        expect(execCommand).not.toHaveBeenCalled()
+    })
+
+    it('falls back to execCommand when clipboard api write fails', async () => {
+        const writeText = vi.fn(async () => {
+            throw new Error('clipboard denied')
+        })
+        Object.defineProperty(navigator, 'clipboard', {
+            configurable: true,
+            value: { writeText }
+        })
+        const execCommand = vi.mocked(document.execCommand)
+        execCommand.mockReturnValue(true)
+
+        await safeCopyToClipboard('fallback')
+
+        expect(writeText).toHaveBeenCalledWith('fallback')
+        expect(execCommand).toHaveBeenCalledWith('copy')
+    })
+
+    it('throws when both modern and legacy copy strategies fail', async () => {
+        Object.defineProperty(navigator, 'clipboard', {
+            configurable: true,
+            value: undefined
+        })
+        const execCommand = vi.mocked(document.execCommand)
+        execCommand.mockReturnValue(false)
+
+        await expect(safeCopyToClipboard('x')).rejects.toThrow('Copy to clipboard failed')
+    })
+})
diff --git a/web/src/lib/clipboard.ts b/web/src/lib/clipboard.ts
index 79dc74b7..38a29e87 100644
--- a/web/src/lib/clipboard.ts
+++ b/web/src/lib/clipboard.ts
@@ -1,6 +1,62 @@
-export function safeCopyToClipboard(text: string): Promise<void> {
-    if (navigator.clipboard?.writeText) {
-        return navigator.clipboard.writeText(text)
+function copyWithExecCommand(text: string): boolean {
+    if (typeof document === 'undefined' || !document.body) {
+        return false
     }
-    return Promise.reject(new Error('Clipboard API not available'))
+
+    const textarea = document.createElement('textarea')
+    textarea.value = text
+    textarea.setAttribute('readonly', 'true')
+    textarea.style.position = 'fixed'
+    textarea.style.top = '0'
+    textarea.style.left = '0'
+    textarea.style.width = '1px'
+    textarea.style.height = '1px'
+    textarea.style.padding = '0'
+    textarea.style.border = '0'
+    textarea.style.opacity = '0'
+    textarea.style.pointerEvents = 'none'
+
+    const activeElement = document.activeElement instanceof HTMLElement ? document.activeElement : null
+    const selection = document.getSelection()
+    const previousRange = selection && selection.rangeCount > 0 ? selection.getRangeAt(0) : null
+
+    document.body.appendChild(textarea)
+    textarea.focus()
+    textarea.select()
+    textarea.setSelectionRange(0, textarea.value.length)
+
+    let copied = false
+    try {
+        copied = document.execCommand('copy')
+    } catch {
+        copied = false
+    } finally {
+        document.body.removeChild(textarea)
+        if (selection) {
+            selection.removeAllRanges()
+            if (previousRange) {
+                selection.addRange(previousRange)
+            }
+        }
+        activeElement?.focus()
+    }
+
+    return copied
+}
+
+export async function safeCopyToClipboard(text: string): Promise<void> {
+    if (typeof navigator !== 'undefined' && navigator.clipboard?.writeText) {
+        try {
+            await navigator.clipboard.writeText(text)
+            return
+        } catch {
+            // Fall through to legacy copy strategy.
+        }
+    }
+
+    if (copyWithExecCommand(text)) {
+        return
+    }
+
+    throw new Error('Copy to clipboard failed')
 }
diff --git a/web/src/lib/locales/en.ts b/web/src/lib/locales/en.ts
index 83275612..342ac5c4 100644
--- a/web/src/lib/locales/en.ts
+++ b/web/src/lib/locales/en.ts
@@ -88,6 +88,7 @@ export default {
   'button.close': 'Close',
   'button.dismiss': 'Dismiss',
   'button.copy': 'Copy',
+  'button.paste': 'Paste',
 
   // New session form
   'newSession.machine': 'Machine',
@@ -136,6 +137,9 @@ export default {
   'terminal.commandArgs': 'Command args',
   'terminal.stdout': 'Stdout',
   'terminal.stderr': 'Stderr',
+  'terminal.paste.fallbackTitle': 'Paste input',
+  'terminal.paste.fallbackDescription': 'Clipboard read is unavailable. Paste your text below.',
+  'terminal.paste.placeholder': 'Paste terminal input here…',
 
   // Code block
   'code.copy': 'Copy',
diff --git a/web/src/lib/locales/zh-CN.ts b/web/src/lib/locales/zh-CN.ts
index 48c75d51..33e5b1f3 100644
--- a/web/src/lib/locales/zh-CN.ts
+++ b/web/src/lib/locales/zh-CN.ts
@@ -90,6 +90,7 @@ export default {
   'button.close': '关闭',
   'button.dismiss': '忽略',
   'button.copy': '复制',
+  'button.paste': '粘贴',
 
   // New session form
   'newSession.machine': '机器',
@@ -138,6 +139,9 @@ export default {
   'terminal.commandArgs': '命令参数',
   'terminal.stdout': '标准输出',
   'terminal.stderr': '标准错误',
+  'terminal.paste.fallbackTitle': '粘贴输入',
+  'terminal.paste.fallbackDescription': '无法读取剪贴板，请在下方粘贴文本。',
+  'terminal.paste.placeholder': '在此粘贴终端输入…',
 
   // Code block
   'code.copy': '复制',
diff --git a/web/src/routes/sessions/file.tsx b/web/src/routes/sessions/file.tsx
index 179a29b1..dd3a96bb 100644
--- a/web/src/routes/sessions/file.tsx
+++ b/web/src/routes/sessions/file.tsx
@@ -11,6 +11,8 @@ import { queryKeys } from '@/lib/query-keys'
 import { langAlias, useShikiHighlighter } from '@/lib/shiki'
 import { decodeBase64 } from '@/lib/utils'
 
+const MAX_COPYABLE_FILE_BYTES = 1_000_000
+
 function decodePath(value: string): string {
     if (!value) return ''
     const decoded = decodeBase64(value)
@@ -94,6 +96,10 @@ function resolveLanguage(path: string): string | undefined {
     return langAlias[ext] ?? ext
 }
 
+function getUtf8ByteLength(value: string): number {
+    return new TextEncoder().encode(value).length
+}
+
 function isBinaryContent(content: string): boolean {
     if (!content) return false
     if (content.includes('\0')) return true
@@ -112,7 +118,8 @@ function extractCommandError(result: GitCommandResponse | undefined): string | n
 
 export default function FilePage() {
     const { api } = useAppContext()
-    const { copied, copy } = useCopyToClipboard()
+    const { copied: pathCopied, copy: copyPath } = useCopyToClipboard()
+    const { copied: contentCopied, copy: copyContent } = useCopyToClipboard()
     const goBack = useAppGoBack()
     const { sessionId } = useParams({ from: '/sessions/$sessionId/file' })
     const search = useSearch({ from: '/sessions/$sessionId/file' })
@@ -160,6 +167,14 @@ export default function FilePage() {
 
     const language = useMemo(() => resolveLanguage(filePath), [filePath])
     const highlighted = useShikiHighlighter(decodedContent, language)
+    const contentSizeBytes = useMemo(
+        () => (decodedContent ? getUtf8ByteLength(decodedContent) : 0),
+        [decodedContent]
+    )
+    const canCopyContent = fileContentResult?.success === true
+        && !binaryFile
+        && decodedContent.length > 0
+        && contentSizeBytes <= MAX_COPYABLE_FILE_BYTES
 
     const [displayMode, setDisplayMode] = useState<'diff' | 'file'>('diff')
 
@@ -204,11 +219,11 @@ export default function FilePage() {
                     <span className="min-w-0 flex-1 truncate text-xs text-[var(--app-hint)]">{filePath}</span>
                     <button
                         type="button"
-                        onClick={() => copy(filePath)}
+                        onClick={() => copyPath(filePath)}
                         className="shrink-0 rounded p-1 text-[var(--app-hint)] hover:bg-[var(--app-subtle-bg)] hover:text-[var(--app-fg)] transition-colors"
                         title="Copy path"
                     >
-                        {copied ? <CheckIcon className="h-3.5 w-3.5" /> : <CopyIcon className="h-3.5 w-3.5" />}
+                        {pathCopied ? <CheckIcon className="h-3.5 w-3.5" /> : <CopyIcon className="h-3.5 w-3.5" />}
                     </button>
                 </div>
             </div>
@@ -257,9 +272,21 @@ export default function FilePage() {
                         <div className="text-sm text-[var(--app-hint)]">{diffError}</div>
                     ) : displayMode === 'file' ? (
                         decodedContent ? (
-                            <pre className="shiki overflow-auto rounded-md bg-[var(--app-code-bg)] p-3 text-xs font-mono">
-                                <code>{highlighted ?? decodedContent}</code>
-                            </pre>
+                            <div className="relative">
+                                {canCopyContent ? (
+                                    <button
+                                        type="button"
+                                        onClick={() => copyContent(decodedContent)}
+                                        className="absolute right-2 top-2 z-10 rounded p-1 text-[var(--app-hint)] hover:bg-[var(--app-subtle-bg)] hover:text-[var(--app-fg)] transition-colors"
+                                        title="Copy file content"
+                                    >
+                                        {contentCopied ? <CheckIcon className="h-3.5 w-3.5" /> : <CopyIcon className="h-3.5 w-3.5" />}
+                                    </button>
+                                ) : null}
+                                <pre className="shiki overflow-auto rounded-md bg-[var(--app-code-bg)] p-3 pr-8 text-xs font-mono">
+                                    <code>{highlighted ?? decodedContent}</code>
+                                </pre>
+                            </div>
                         ) : (
                             <div className="text-sm text-[var(--app-hint)]">File is empty.</div>
                         )
diff --git a/web/src/routes/sessions/terminal.test.tsx b/web/src/routes/sessions/terminal.test.tsx
new file mode 100644
index 00000000..2f294342
--- /dev/null
+++ b/web/src/routes/sessions/terminal.test.tsx
@@ -0,0 +1,100 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { I18nProvider } from '@/lib/i18n-context'
+import TerminalPage from './terminal'
+
+const writeMock = vi.fn()
+
+vi.mock('@tanstack/react-router', () => ({
+    useParams: () => ({ sessionId: 'session-1' })
+}))
+
+vi.mock('@/lib/app-context', () => ({
+    useAppContext: () => ({
+        api: null,
+        token: 'test-token',
+        baseUrl: 'http://localhost:3000'
+    })
+}))
+
+vi.mock('@/hooks/useAppGoBack', () => ({
+    useAppGoBack: () => vi.fn()
+}))
+
+vi.mock('@/hooks/queries/useSession', () => ({
+    useSession: () => ({
+        session: {
+            id: 'session-1',
+            active: true,
+            metadata: { path: '/tmp/project' }
+        }
+    })
+}))
+
+vi.mock('@/hooks/useTerminalSocket', () => ({
+    useTerminalSocket: () => ({
+        state: { status: 'connected' as const },
+        connect: vi.fn(),
+        write: writeMock,
+        resize: vi.fn(),
+        disconnect: vi.fn(),
+        onOutput: vi.fn(),
+        onExit: vi.fn()
+    })
+}))
+
+vi.mock('@/hooks/useLongPress', () => ({
+    useLongPress: ({ onClick }: { onClick: () => void }) => ({
+        onClick
+    })
+}))
+
+vi.mock('@/components/Terminal/TerminalView', () => ({
+    TerminalView: () => <div data-testid="terminal-view" />
+}))
+
+function renderWithProviders() {
+    return render(
+        <I18nProvider>
+            <TerminalPage />
+        </I18nProvider>
+    )
+}
+
+describe('TerminalPage paste behavior', () => {
+    beforeEach(() => {
+        vi.clearAllMocks()
+    })
+
+    it('does not open manual paste dialog when clipboard text is empty', async () => {
+        const readText = vi.fn(async () => '')
+        Object.defineProperty(navigator, 'clipboard', {
+            configurable: true,
+            value: { readText }
+        })
+
+        renderWithProviders()
+        fireEvent.click(screen.getAllByRole('button', { name: 'Paste' })[0])
+
+        await waitFor(() => {
+            expect(readText).toHaveBeenCalledTimes(1)
+        })
+        expect(writeMock).not.toHaveBeenCalled()
+        expect(screen.queryByText('Paste input')).not.toBeInTheDocument()
+    })
+
+    it('opens manual paste dialog when clipboard read fails', async () => {
+        const readText = vi.fn(async () => {
+            throw new Error('blocked')
+        })
+        Object.defineProperty(navigator, 'clipboard', {
+            configurable: true,
+            value: { readText }
+        })
+
+        renderWithProviders()
+        fireEvent.click(screen.getAllByRole('button', { name: 'Paste' })[0])
+
+        expect(await screen.findByText('Paste input')).toBeInTheDocument()
+    })
+})
diff --git a/web/src/routes/sessions/terminal.tsx b/web/src/routes/sessions/terminal.tsx
index 5ccc9fe4..0aba34b6 100644
--- a/web/src/routes/sessions/terminal.tsx
+++ b/web/src/routes/sessions/terminal.tsx
@@ -7,8 +7,17 @@ import { useAppGoBack } from '@/hooks/useAppGoBack'
 import { useSession } from '@/hooks/queries/useSession'
 import { useTerminalSocket } from '@/hooks/useTerminalSocket'
 import { useLongPress } from '@/hooks/useLongPress'
+import { useTranslation } from '@/lib/use-translation'
 import { TerminalView } from '@/components/Terminal/TerminalView'
 import { LoadingState } from '@/components/LoadingState'
+import { Button } from '@/components/ui/button'
+import {
+    Dialog,
+    DialogContent,
+    DialogDescription,
+    DialogHeader,
+    DialogTitle
+} from '@/components/ui/dialog'
 function BackIcon() {
     return (
         <svg
@@ -170,6 +179,7 @@ function QuickKeyButton(props: {
 }
 
 export default function TerminalPage() {
+    const { t } = useTranslation()
     const { sessionId } = useParams({ from: '/sessions/$sessionId/terminal' })
     const { api, token, baseUrl } = useAppContext()
     const goBack = useAppGoBack()
@@ -188,6 +198,8 @@ export default function TerminalPage() {
     const [exitInfo, setExitInfo] = useState<{ code: number | null; signal: string | null } | null>(null)
     const [ctrlActive, setCtrlActive] = useState(false)
     const [altActive, setAltActive] = useState(false)
+    const [pasteDialogOpen, setPasteDialogOpen] = useState(false)
+    const [manualPasteText, setManualPasteText] = useState('')
 
     const {
         state: terminalState,
@@ -312,6 +324,48 @@ export default function TerminalPage() {
     }, [terminalState.status])
 
     const quickInputDisabled = !session?.active || terminalState.status !== 'connected'
+    const writePlainInput = useCallback((text: string) => {
+        if (!text || quickInputDisabled) {
+            return false
+        }
+        write(text)
+        resetModifiers()
+        terminalRef.current?.focus()
+        return true
+    }, [quickInputDisabled, write, resetModifiers])
+
+    const handlePasteAction = useCallback(async () => {
+        if (quickInputDisabled) {
+            return
+        }
+        const readClipboard = navigator.clipboard?.readText
+        if (readClipboard) {
+            try {
+                const clipboardText = await readClipboard.call(navigator.clipboard)
+                if (!clipboardText) {
+                    return
+                }
+                if (writePlainInput(clipboardText)) {
+                    return
+                }
+            } catch {
+                // Fall through to manual paste modal.
+            }
+        }
+        setManualPasteText('')
+        setPasteDialogOpen(true)
+    }, [quickInputDisabled, writePlainInput])
+
+    const handleManualPasteSubmit = useCallback(() => {
+        if (!manualPasteText.trim()) {
+            return
+        }
+        if (writePlainInput(manualPasteText)) {
+            setPasteDialogOpen(false)
+            setManualPasteText('')
+        }
+    }, [manualPasteText, writePlainInput])
+
     const handleQuickInput = useCallback(
         (sequence: string) => {
             if (quickInputDisabled) {
@@ -406,6 +460,16 @@ export default function TerminalPage() {
             <div className="bg-[var(--app-bg)] border-t border-[var(--app-border)] pb-[env(safe-area-inset-bottom)]">
                 <div className="mx-auto w-full max-w-content px-3">
                     <div className="flex flex-col gap-2 py-2">
+                        <button
+                            type="button"
+                            onClick={() => {
+                                void handlePasteAction()
+                            }}
+                            disabled={quickInputDisabled}
+                            className="w-full rounded-md border border-[var(--app-border)] bg-[var(--app-secondary-bg)] px-3 py-2 text-sm font-medium text-[var(--app-fg)] transition-colors hover:bg-[var(--app-subtle-bg)] focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-[var(--app-button)] disabled:cursor-not-allowed disabled:opacity-50"
+                        >
+                            {t('button.paste')}
+                        </button>
                         {QUICK_INPUT_ROWS.map((row, rowIndex) => (
                             <div
                                 key={`terminal-quick-row-${rowIndex}`}
@@ -432,6 +496,52 @@ export default function TerminalPage() {
                     </div>
                 </div>
             </div>
+
+            <Dialog
+                open={pasteDialogOpen}
+                onOpenChange={(open) => {
+                    setPasteDialogOpen(open)
+                    if (!open) {
+                        setManualPasteText('')
+                    }
+                }}
+            >
+                <DialogContent className="max-w-md">
+                    <DialogHeader>
+                        <DialogTitle>{t('terminal.paste.fallbackTitle')}</DialogTitle>
+                        <DialogDescription>
+                            {t('terminal.paste.fallbackDescription')}
+                        </DialogDescription>
+                    </DialogHeader>
+                    <textarea
+                        value={manualPasteText}
+                        onChange={(event) => setManualPasteText(event.target.value)}
+                        placeholder={t('terminal.paste.placeholder')}
+                        className="mt-2 min-h-32 w-full resize-y rounded-md border border-[var(--app-border)] bg-[var(--app-bg)] p-2 text-sm focus:outline-none focus:ring-2 focus:ring-[var(--app-link)]"
+                        autoCapitalize="none"
+                        autoCorrect="off"
+                    />
+                    <div className="mt-3 flex justify-end gap-2">
+                        <Button
+                            type="button"
+                            variant="secondary"
+                            onClick={() => {
+                                setPasteDialogOpen(false)
+                                setManualPasteText('')
+                            }}
+                        >
+                            {t('button.cancel')}
+                        </Button>
+                        <Button
+                            type="button"
+                            onClick={handleManualPasteSubmit}
+                            disabled={!manualPasteText.trim()}
+                        >
+                            {t('button.paste')}
+                        </Button>
+                    </div>
+                </DialogContent>
+            </Dialog>
         </div>
     )
 }