If you’re used to creating the groundwork of your presentations in Slide Master View in the PowerPoint desktop application, you’ve probably noticed that PowerPoint for the web doesn’t have a slide master.
If you have the PowerPoint desktop application, you can open and create your presentation using the slide master there. Here’s how:
In PowerPoint for the web, click Open in PowerPoint.
For help using slide masters on a Windows PC or Macintosh, see What is a slide master?