How to Show the Menu Bar on an External Monitor (Mac)

Whether your external monitor gets its own menu bar comes down to one toggle: Displays have separate Spaces. It's on by default, so every screen normally shows a menu bar — if yours doesn't, someone turned it off. Here's the switch, what the dimmed bar means, and how to pick the main display.

Turn on a menu bar for every display

1. Open System Settings → Desktop & Dock.
2. Scroll down to the Mission Control section.
3. Turn on Displays have separate Spaces.
4. Log out (Apple menu → Log Out) and back in — the setting only applies at login.

With it on, every connected display gets its own menu bar, its own set of Spaces, and can run its own full-screen app. With it off, all displays form one giant continuous Space and only the main display gets a menu bar — that's the classic "my second monitor has no menu bar" situation.

Why one menu bar looks dimmed

This is normal, not a rendering bug. The menu bar on the display containing the currently active app is drawn at full strength; menu bars on the other displays appear dimmed or more translucent. All of them work — click any menu on any display and it responds, and the menus always belong to whichever app is frontmost. The dimming is just macOS telling you where keyboard focus lives.

The same switch from Terminal

The setting is stored in the Spaces preferences domain. Note the inverted logic: spans-displays set to false means displays do not span, i.e. separate Spaces (and per-display menu bars) are on.

# Give every display its own Space and menu bar
defaults write com.apple.spaces spans-displays -bool false

# Undo: restore the default state of the key
defaults delete com.apple.spaces spans-displays

Either way you must log out and back in before anything changes — there's no process you can restart to apply it live.

Choose which monitor is the main display

Even with a menu bar everywhere, one display is still the main one: it gets new windows by default, the Dock's home, and app dialogs.

1. Open System Settings → Displays.
2. Click Arrange… to see the layout of your screens.
3. Drag the thin white strip (the menu bar marker) from one display's thumbnail to the other, or select a display and set Use as to Main display.

While you're in the Arrange sheet, drag the display thumbnails so their on-screen positions match the physical desk layout — that fixes the cursor "teleporting" between screens at the wrong edge.

The trade-off to know about

With separate Spaces on, a full-screen app on one monitor no longer blacks out the other — a huge win for multi-monitor work. The cost: you can't stretch a single window across both displays anymore, because each display is its own Space. If you genuinely need one window spanning two screens, turn the setting off and live with the single menu bar.

One more arrangement worth knowing: clamshell mode. Close the MacBook's lid while it's connected to power, an external display, and an external keyboard, and the external screen becomes the only screen — menu bar included, no settings required. If you've been keeping the lid open just for the menu bar, you don't need to. And if the external display shows a menu bar but the wrong things on it — icons missing compared to your built-in display — remember that menu bar extras appear on every bar, but the active-display dimming can make them look faded rather than absent.

Now sort out the Dock

The menu bar follows this setting, but the Dock plays by its own rules — it lives on one display and hops over when you linger at another screen's bottom edge. Here's how to move the Dock between displays without the accidental jumps.