diff --git a/packages/bruno-app/src/components/AppTitleBar/index.js b/packages/bruno-app/src/components/AppTitleBar/index.js
index 1010d0a88..3551556dd 100644
--- a/packages/bruno-app/src/components/AppTitleBar/index.js
+++ b/packages/bruno-app/src/components/AppTitleBar/index.js
@@ -52,6 +52,14 @@ const AppTitleBar = () => {
     const { ipcRenderer } = window;
     if (!ipcRenderer) return;
 
+    ipcRenderer.invoke('renderer:window-is-fullscreen')
+      .then((fullscreen) => {
+        setIsFullScreen(fullscreen);
+      })
+      .catch((error) => {
+        console.error('Error getting initial fullscreen state:', error);
+      });
+
     const removeEnterFullScreenListener = ipcRenderer.on('main:enter-full-screen', () => {
       setIsFullScreen(true);
     });
diff --git a/packages/bruno-app/src/components/AppTitleBar/index.spec.js b/packages/bruno-app/src/components/AppTitleBar/index.spec.js
new file mode 100644
index 000000000..ec57c3f21
--- /dev/null
+++ b/packages/bruno-app/src/components/AppTitleBar/index.spec.js
@@ -0,0 +1,128 @@
+import '@testing-library/jest-dom';
+import React from 'react';
+import { render, waitFor, act } from '@testing-library/react';
+import { ThemeProvider } from 'styled-components';
+import { Provider } from 'react-redux';
+import { configureStore } from '@reduxjs/toolkit';
+
+jest.mock('ui/MenuDropdown', () => ({ children }) => <div>{children}</div>);
+jest.mock('ui/ActionIcon', () => ({ children, onClick, label }) => (
+  <button onClick={onClick} aria-label={label}>{children}</button>
+));
+jest.mock('components/ResponsePane/ResponseLayoutToggle', () => () => null);
+
+import AppTitleBar from './index';
+
+const theme = {
+  text: '#333',
+  sidebar: {
+    bg: '#fff',
+    color: '#333',
+    muted: '#888',
+    collection: { item: { hoverBg: '#eee' } }
+  },
+  dropdown: { color: '#333', mutedText: '#888', hoverBg: '#eee' }
+};
+
+const mockStore = configureStore({
+  reducer: {
+    workspaces: (state = { workspaces: [], activeWorkspaceUid: null }) => state,
+    app: (state = { preferences: {}, sidebarCollapsed: false }) => state,
+    logs: (state = { isConsoleOpen: false }) => state
+  }
+});
+
+const renderWithProviders = () => render(
+  <Provider store={mockStore}>
+    <ThemeProvider theme={theme}>
+      <AppTitleBar />
+    </ThemeProvider>
+  </Provider>
+);
+
+const getTitleBar = (container) => container.querySelector('.app-titlebar');
+
+const mockInvokeWithFullscreen = (isFullScreen) => jest.fn((channel) => {
+  if (channel === 'renderer:window-is-fullscreen') return Promise.resolve(isFullScreen);
+  return Promise.resolve(false);
+});
+
+describe('AppTitleBar — fullscreen state sync', () => {
+  let ipcListeners;
+
+  beforeEach(() => {
+    ipcListeners = {};
+    window.ipcRenderer = {
+      invoke: jest.fn().mockResolvedValue(false),
+      send: jest.fn(),
+      on: jest.fn((channel, cb) => {
+        ipcListeners[channel] = cb;
+        return jest.fn();
+      })
+    };
+  });
+
+  afterEach(() => {
+    delete window.ipcRenderer;
+  });
+
+  describe('initial state on mount', () => {
+    it('should query the main process for current fullscreen state', async () => {
+      renderWithProviders();
+      await waitFor(() => {
+        expect(window.ipcRenderer.invoke).toHaveBeenCalledWith('renderer:window-is-fullscreen');
+      });
+    });
+
+    it('should apply fullscreen class when window is already fullscreen at mount', async () => {
+      window.ipcRenderer.invoke = mockInvokeWithFullscreen(true);
+
+      const { container } = renderWithProviders();
+
+      await waitFor(() => {
+        expect(getTitleBar(container)).toHaveClass('fullscreen');
+      });
+    });
+
+    it('should not apply fullscreen class when window is windowed at mount', async () => {
+      const { container } = renderWithProviders();
+
+      await waitFor(() => {
+        expect(window.ipcRenderer.invoke).toHaveBeenCalledWith('renderer:window-is-fullscreen');
+      });
+      expect(getTitleBar(container)).not.toHaveClass('fullscreen');
+    });
+  });
+
+  describe('fullscreen transitions after mount', () => {
+    it('should add fullscreen class on main:enter-full-screen event', async () => {
+      const { container } = renderWithProviders();
+
+      await waitFor(() => {
+        expect(window.ipcRenderer.invoke).toHaveBeenCalledWith('renderer:window-is-fullscreen');
+      });
+
+      act(() => {
+        ipcListeners['main:enter-full-screen']();
+      });
+
+      expect(getTitleBar(container)).toHaveClass('fullscreen');
+    });
+
+    it('should remove fullscreen class on main:leave-full-screen event', async () => {
+      window.ipcRenderer.invoke = mockInvokeWithFullscreen(true);
+
+      const { container } = renderWithProviders();
+
+      await waitFor(() => {
+        expect(getTitleBar(container)).toHaveClass('fullscreen');
+      });
+
+      act(() => {
+        ipcListeners['main:leave-full-screen']();
+      });
+
+      expect(getTitleBar(container)).not.toHaveClass('fullscreen');
+    });
+  });
+});
diff --git a/packages/bruno-electron/src/index.js b/packages/bruno-electron/src/index.js
index db1c7d509..bacd42dd0 100644
--- a/packages/bruno-electron/src/index.js
+++ b/packages/bruno-electron/src/index.js
@@ -275,6 +275,10 @@ app.on('ready', async () => {
     return mainWindow.isMaximized();
   });
 
+  ipcMain.handle('renderer:window-is-fullscreen', () => {
+    return mainWindow.isFullScreen();
+  });
+
   ipcMain.handle('renderer:open-preferences', () => {
     ipcMain.emit('main:open-preferences');
   });