PowerPoint files (.ppt, .pptx, .pps and .ppsx) can sometimes become very large and slow, whether that is due to a large number of slide or heavy use of images you can easily exceed 50mb or another limit you might have. Watch out for oversize image files.
Images don’t need to be much larger than 1024 × 768 pixels (see What resolution should I make my images for PowerPoint slide shows?) at least in most cases. Your powerpoint files are bigger than they need to be if your image exceed this resolution.
PowerPoint can compress images and remove unneeded data:
- Right-click the picture, and then click Format Picture on the shortcut menu.
- In the Format dialog box, click the Picture tab, and then click Compress.
- Under Apply to, do one of the following:
To compress just the current picture, click Selected pictures. To compress all the pictures in your presentation, click All pictures in document.
- Under Change resolution, do one of the following:
If your presentation will be used for a screen show, click Web/Screen. If you plan to distribute your presentation as printed pages, click Print.
- Under Options, select the Compress pictures check box and the Delete cropped areas of pictures check box.
- Click OK.
- If prompted, click Apply in the Compress Pictures dialog box.
PowerPoint compresses the picture(s) for you automatically and you got a much smaller PowerPoint file.