Quick summary
To change slides to poster size in PowerPoint Online, open the Design tab, select Custom Slide Size, and enter your desired width and height values. This lets you format any presentation as a large-format poster directly in your browser without desktop software.
Steps
- Inside the slide canvas, go to the top menu bar and click Design.
- Find and click Slide Size in the ribbon.
- Tap Custom Slide Size to proceed.
- Enter your preferred poster dimensions by typing values into the Width and Height input fields, or adjust them using the spin buttons.
- Select your preferred Slide Orientation and Slide Scale.
- Click OK to apply the changes.
- Your PowerPoint Online slides are now set to poster size.