diff --git a/application/AppHandlers.globalHotkeys.test.ts b/application/AppHandlers.globalHotkeys.test.ts
index 78d1448b3..f79b46ad3 100644
--- a/application/AppHandlers.globalHotkeys.test.ts
+++ b/application/AppHandlers.globalHotkeys.test.ts
@@ -674,3 +674,53 @@ test('connection log host snapshot includes custom host icon fields', () => {
     },
   );
 });
+
+test('toggleOpacity hotkey invokes toggleWindowOpacity', () => {
+  let called = false;
+  const noop = () => {};
+
+  executeHotkeyActionImpl(
+    () => ({
+      IS_DEV: false,
+      MOVE_FOCUS_DEBOUNCE_MS: 0,
+      activeTabStore: { getActiveTabId: () => 'vault' },
+      addConnectionLogRef: { current: noop },
+      closeSession: noop,
+      closeTabInFlightRef: { current: false },
+      closeWorkspace: noop,
+      collectSessionIds: () => [],
+      confirmIfBusyLocalTerminal: async () => true,
+      createLocalTerminalWithCurrentShell: noop,
+      editorTabs: [],
+      fromEditorTabId: () => null,
+      handleOpenSettingsRef: { current: noop },
+      handleRequestCloseEditorTabRef: { current: noop },
+      isEditorTabId: () => false,
+      isQuickSwitcherOpen: false,
+      lastMoveFocusTimeRef: { current: 0 },
+      moveFocusInWorkspace: noop,
+      orderedTabs: [],
+      resolveCloseIntent: () => ({ kind: 'noop' }),
+      resolveSnippetsShortcutIntent: () => ({ kind: 'noop' }),
+      sessions: [],
+      setActiveTabId: noop,
+      setAddToWorkspaceDialog: noop,
+      setIsQuickSwitcherOpen: noop,
+      setNavigateToSection: noop,
+      settings: { showSftpTab: true, shellOnlyTabNumberShortcuts: false },
+      splitSessionWithCurrentShell: noop,
+      systemInfoRef: { current: { username: 'user', hostname: 'host' } },
+      toEditorTabId: (id: string) => `editor:${id}`,
+      toggleBroadcast: noop,
+      toggleScriptsSidePanelRef: { current: noop },
+      toggleSidePanelRef: { current: noop },
+      toggleWindowOpacity: () => { called = true; },
+      toggleWorkspaceViewMode: noop,
+      workspaces: [],
+    }),
+    'toggleOpacity',
+    { key: 'u', code: 'KeyU', ctrlKey: true, shiftKey: true } as KeyboardEvent,
+  );
+
+  assert.equal(called, true);
+});
diff --git a/application/app/AppHandlers.ts b/application/app/AppHandlers.ts
index 75aad2d51..166f2681a 100644
--- a/application/app/AppHandlers.ts
+++ b/application/app/AppHandlers.ts
@@ -702,7 +702,7 @@ export async function closeTabsBatchImpl(getCtx: AppContextGetter, targetIds: st
 }
 
 export function executeHotkeyActionImpl(getCtx: AppContextGetter, action: string, e: KeyboardEvent) {
-  const { IS_DEV, MOVE_FOCUS_DEBOUNCE_MS, activeTabStore, addConnectionLogRef, closePluginViewTab, closeSession, closeTabInFlightRef, closeWorkspace, collectSessionIds, confirmIfBusyLocalTerminal, createLocalTerminalWithCurrentShell, editorTabs, fromEditorTabId, handleOpenSettingsRef, handleRequestCloseEditorTabRef, isEditorTabId, isPluginViewTabId, isQuickSwitcherOpen, lastMoveFocusTimeRef, moveFocusInWorkspace, orderedTabs, resolveCloseIntent, resolveSnippetsShortcutIntent, sessions, setActiveTabId, setAddToWorkspaceDialog, setIsQuickSwitcherOpen, setNavigateToSection, settings, sftpPaneMagnificationRef, splitSessionWithCurrentShell, systemInfoRef, terminalPaneMagnificationRef, toEditorTabId, toggleBroadcast, toggleScriptsSidePanelRef, toggleSidePanelRef, workspaces } = getCtx();
+  const { IS_DEV, MOVE_FOCUS_DEBOUNCE_MS, activeTabStore, addConnectionLogRef, closePluginViewTab, closeSession, closeTabInFlightRef, closeWorkspace, collectSessionIds, confirmIfBusyLocalTerminal, createLocalTerminalWithCurrentShell, editorTabs, fromEditorTabId, handleOpenSettingsRef, handleRequestCloseEditorTabRef, isEditorTabId, isPluginViewTabId, isQuickSwitcherOpen, lastMoveFocusTimeRef, moveFocusInWorkspace, orderedTabs, resolveCloseIntent, resolveSnippetsShortcutIntent, sessions, setActiveTabId, setAddToWorkspaceDialog, setIsQuickSwitcherOpen, setNavigateToSection, settings, sftpPaneMagnificationRef, splitSessionWithCurrentShell, systemInfoRef, terminalPaneMagnificationRef, toEditorTabId, toggleBroadcast, toggleScriptsSidePanelRef, toggleSidePanelRef, toggleWindowOpacity, workspaces } = getCtx();
 {
     const shortcutTabs = buildNumberShortcutTabTargets({
       showSftpTab: settings.showSftpTab ?? true,
@@ -892,6 +892,9 @@ export function executeHotkeyActionImpl(getCtx: AppContextGetter, action: string
           setNavigateToSection('snippets');
         }
         break;
+      case 'toggleOpacity':
+        toggleWindowOpacity();
+        break;
       case 'toggleSidePanel':
         toggleSidePanelRef.current?.();
         break;
diff --git a/application/app/AppSideEffects.tsx b/application/app/AppSideEffects.tsx
index b5172d8be..c432eb2a7 100755
--- a/application/app/AppSideEffects.tsx
+++ b/application/app/AppSideEffects.tsx
@@ -144,6 +144,7 @@ export function AppSideEffects() {
     showSftpTab,
     shellOnlyTabNumberShortcuts,
     workspaceFocusStyle,
+    toggleWindowOpacity,
   } = settings;
 
   useTerminalKeyboardFocus(hotkeyScheme !== 'disabled' && !disableTerminalFontZoom);
@@ -1076,6 +1077,7 @@ export function AppSideEffects() {
       toggleBroadcast,
       toggleScriptsSidePanelRef,
       toggleSidePanelRef,
+      toggleWindowOpacity,
       toggleWorkspaceViewMode,
       workspaces: workspacesRefForHotkeys.current,
     }), action, e);
@@ -1088,6 +1090,7 @@ export function AppSideEffects() {
     splitSessionWithCurrentShell,
     moveFocusInWorkspace,
     toggleBroadcast,
+    toggleWindowOpacity,
     toggleWorkspaceViewMode,
     confirmIfBusyLocalTerminal,
   ]);
diff --git a/application/i18n/locales/ru/core.ts b/application/i18n/locales/ru/core.ts
index c12563009..064f1f419 100644
--- a/application/i18n/locales/ru/core.ts
+++ b/application/i18n/locales/ru/core.ts
@@ -866,6 +866,7 @@ export const ruCoreMessages: Messages = {
   'settings.shortcuts.binding.new-workspace': 'Новая рабочая область',
   'settings.shortcuts.binding.snippets': 'Открыть сниппеты',
   'settings.shortcuts.binding.broadcast': 'Переключить режим трансляции',
+  'settings.shortcuts.binding.toggle-opacity': 'Переключить прозрачность окна',
   'settings.shortcuts.binding.toggle-side-panel': 'Переключить боковую панель',
   'settings.shortcuts.binding.sftp-copy': 'Копировать файл',
   'settings.shortcuts.binding.sftp-cut': 'Вырезать файл',
diff --git a/application/i18n/locales/zh-CN/terminal.ts b/application/i18n/locales/zh-CN/terminal.ts
index 4a21c5353..0621487c5 100644
--- a/application/i18n/locales/zh-CN/terminal.ts
+++ b/application/i18n/locales/zh-CN/terminal.ts
@@ -565,6 +565,7 @@ export const zhCNTerminalMessages: Messages = {
   'settings.shortcuts.binding.new-workspace': '新建工作区',
   'settings.shortcuts.binding.snippets': '打开代码片段',
   'settings.shortcuts.binding.broadcast': '切换广播模式',
+  'settings.shortcuts.binding.toggle-opacity': '切换窗口透明度',
   'settings.shortcuts.binding.toggle-side-panel': '切换侧边栏',
   'settings.shortcuts.binding.sftp-copy': '复制文件',
   'settings.shortcuts.binding.sftp-cut': '剪切文件',
diff --git a/application/i18n/locales/zh-TW/terminal.ts b/application/i18n/locales/zh-TW/terminal.ts
index f51fd783a..cae96e31b 100644
--- a/application/i18n/locales/zh-TW/terminal.ts
+++ b/application/i18n/locales/zh-TW/terminal.ts
@@ -565,6 +565,7 @@ export const zhTWTerminalMessages: Messages = {
   'settings.shortcuts.binding.new-workspace': '新增工作區',
   'settings.shortcuts.binding.snippets': '開啟程式碼片段',
   'settings.shortcuts.binding.broadcast': '切換廣播模式',
+  'settings.shortcuts.binding.toggle-opacity': '切換視窗透明度',
   'settings.shortcuts.binding.toggle-side-panel': '切換側邊欄',
   'settings.shortcuts.binding.sftp-copy': '複製檔案',
   'settings.shortcuts.binding.sftp-cut': '剪下檔案',
diff --git a/application/state/useGlobalHotkeys.ts b/application/state/useGlobalHotkeys.ts
index 0c66cd699..0ea5da9dd 100644
--- a/application/state/useGlobalHotkeys.ts
+++ b/application/state/useGlobalHotkeys.ts
@@ -39,6 +39,7 @@ export const getAppLevelActions = (): Set<string> => {
     'togglePaneZoom',
     'openLocal',
     'openSettings',
+    'toggleOpacity',
   ]);
 };
 
diff --git a/application/state/useSettingsState.ts b/application/state/useSettingsState.ts
index fc6e97a86..6963086e4 100644
--- a/application/state/useSettingsState.ts
+++ b/application/state/useSettingsState.ts
@@ -595,6 +595,18 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
       return incoming;
     });
   }, []);
+  // Tracks the user's preferred transparency level (last value below 100%) so
+  // Cmd+U can restore it after toggling transparency off. Session-only (useRef),
+  // never persisted — matches iTerm2's session-level toggle behavior.
+  const lastNonFullOpacityRef = useRef<number | null>(windowOpacity < 1.0 ? windowOpacity : null);
+  useEffect(() => {
+    if (windowOpacity < 1.0) {
+      lastNonFullOpacityRef.current = windowOpacity;
+    }
+  }, [windowOpacity]);
+  const toggleWindowOpacity = useCallback(() => {
+    setWindowOpacity(windowOpacity < 1.0 ? 1.0 : (lastNonFullOpacityRef.current ?? 0.85));
+  }, [windowOpacity, setWindowOpacity]);
   const [appIconVariant, setAppIconVariantState] = useState<AppIconVariant>(() => {
     const stored = readStoredString(STORAGE_KEY_APP_ICON_VARIANT);
     return resolveAppIconVariant(stored ?? DEFAULT_APP_ICON_VARIANT);
@@ -2110,6 +2122,7 @@ export const useSettingsState = (options: { enableSettingsSync?: boolean; enable
     setGlobalHotkeyEnabled,
     windowOpacity,
     setWindowOpacity,
+    toggleWindowOpacity,
     appIconVariant,
     setAppIconVariant,
     rehydrateAllFromStorage,
diff --git a/components/TopTabsQuickControls.tsx b/components/TopTabsQuickControls.tsx
index 8097d7efb..bedeee0f5 100644
--- a/components/TopTabsQuickControls.tsx
+++ b/components/TopTabsQuickControls.tsx
@@ -107,7 +107,7 @@ export const TopTabsQuickControls: React.FC<TopTabsQuickControlsProps> = ({
                 onClick={() => setIsOpacityExpanded((current) => !current)}
               >
                 <div className="flex min-w-0 items-center gap-2 text-sm">
-                  <Droplets size={14} className="shrink-0 text-muted-foreground" />
+                  <Droplets size={14} className={cn("shrink-0", windowOpacity < 1.0 ? "text-primary" : "text-muted-foreground")} />
                   <span className="truncate">{t('topTabs.windowOpacity')}</span>
                 </div>
                 <div className="flex shrink-0 items-center gap-1.5">
diff --git a/domain/models/keyBindings.ts b/domain/models/keyBindings.ts
index c99c2c205..2ee82d033 100644
--- a/domain/models/keyBindings.ts
+++ b/domain/models/keyBindings.ts
@@ -274,6 +274,7 @@ export const DEFAULT_KEY_BINDINGS: KeyBinding[] = [
   { id: 'broadcast', action: 'broadcast', label: 'Switch the Broadcast Mode', mac: '⌘ + B', pc: 'Ctrl + B', category: 'app' },
   { id: 'toggle-side-panel', action: 'toggleSidePanel', label: 'Toggle Side Panel', mac: '⌘ + \\', pc: 'Ctrl + \\', category: 'app' },
   { id: 'open-settings', action: 'openSettings', label: 'Open Settings', mac: '⌘ + ,', pc: 'Ctrl + ,', category: 'app' },
+  { id: 'toggle-opacity', action: 'toggleOpacity', label: 'Toggle Window Transparency', mac: '⌘ + U', pc: 'Ctrl + Shift + U', category: 'app' },
 
   // SFTP Operations
   { id: 'sftp-copy', action: 'sftpCopy', label: 'Copy Files', mac: '⌘ + C', pc: 'Ctrl + C', category: 'sftp' },