Apply a master slide in Keynote on Mac
To quickly change the look of a slide, you can apply a different master slide to it. If you make changes to a slide’s format and later want to use the original formatting of its master slide, you can reapply the master slide. Reapplying the master slide won’t delete your content.
Apply a different master to a slide
In the Format sidebar, click the Change Master button near the top.
Select a different slide layout.
Tip: You can add a Masters button to the toolbar, which gives you quick access to all slide layouts. To learn more, see Customize the Keynote toolbar on Mac.
Reapply a master to a slide
You can reapply a master to a slide so that text and media placeholders return to their default style and position, the slide background returns to its default color or image, and placeholder objects are shown or hidden as they were by default.
Note: If you’re sharing a presentation with others, you can’t reapply master slides.