To show your Keynote slides on an external screen while keeping presenter notes and controls on your Mac, connect the display, turn off mirroring, then start the slideshow in full-screen mode. Keynote opens the slideshow on an external display by default and the presenter display on your Mac. You can switch screens, choose what the presenter display shows, and rehearse the layout before presenting.

1. Connect the external display and extend your desktop

Connect the screen to power, then connect its video cable to a compatible port on your Mac. Depending on the ports available, you may need an adapter. Mac models support different numbers of external displays, so check your model’s specifications if a second screen is not detected. Apple’s Mac display connection guide covers ports, adapters, display detection, and model limits.

On your Mac, open Apple menu > System Settings > Displays. Select Arrange and make sure the display thumbnails are side by side rather than stacked on top of one another. Stacked displays indicate mirroring; when displays are extended, each screen can show different content. Apple’s Keynote instructions for presenting on a separate display specify turning mirroring off so viewers see the slideshow instead of the presenter display.

2. Start the Keynote slideshow

Open your presentation and select the slide where you want to begin. From the menu bar, choose Play > In Full Screen, then click the Play button in the toolbar. Keynote normally places the slideshow on an external screen and shows the presenter display on your Mac. If the windows appear on the wrong screens, press X to cycle their display assignment until the slideshow and presenter view are where you want them. Apple documents this display-switching shortcut and the default arrangement.

Press Space or Right Arrow to advance through slides or builds, and Left Arrow to go back. To jump to a specific slide, type its number and press Return. Press Esc to stop the slideshow.

3. Choose what appears in the presenter display

Move your pointer over the presenter display to reveal its controls. Open Display Configuration to show or hide items such as the current slide, next slide, presenter notes, clock, timer, and ready-to-advance indicator. To rearrange or resize those items, choose Customise Presenter Display; use Use Auto Layout if you want Keynote to position them automatically. You can also change the presenter-notes font size and invert its colors. These are Keynote controls; they do not change what is on the audience slide. Apple’s display setup guide describes the available presenter-display options.

If notes are missing, add them in the presentation first: click View in the toolbar, choose Show Presenter Notes, select a slide, and type into the notes area below it. Notes are for the presenter and do not appear on the slide. Apple’s presenter-notes guide explains how to add, view, and hide them.

4. Assign screens when you have multiple external displays

With two or more external displays, move the pointer over the primary presenter display and open Display Configuration. Choose Configure beneath a display thumbnail, then select Show Slideshow or Show Presenter Display. You can also configure which presenter items appear on each screen. For example, keep notes on the Mac display and put the current and next slides on another screen. Click Done when the assignments are set. The configuration options depend on the displays connected and recognized by your Mac and Keynote. Apple documents per-display configuration in Keynote.

5. Rehearse the setup and troubleshoot

To arrange the presenter display before connecting the projector or monitor, choose Play > Rehearse Slideshow. The presenter display appears on your Mac; press X to switch between it and the current slide. With an external screen connected, Option-X lets you choose which display to rehearse on. You can test navigation and edit notes while rehearsing; press Esc to stop. Apple’s rehearsal guide documents these options.

If both screens show the same thing, check System Settings > Displays > Arrange and separate any stacked display thumbnails. If the external screen stays blank or is not detected, confirm it has power and that the cable, port, or required adapter is connected correctly. Check your Mac’s display support if you are connecting multiple screens. If the presenter view and slideshow are reversed, press X during playback or set each screen explicitly in Display Configuration.

The reliable setup is an extended Mac desktop with Keynote’s full-screen slideshow on the external screen and the presenter display assigned to your Mac. Rehearsing lets you confirm the screen assignment, notes, and controls before your audience arrives.

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