Optimize Your Powerpoint Slideshow

Large Powerpoint files (50+ megabytes) have become common and depending on the situation (e.g., destination computer), can cause problems. The following links and information are intended to help you minimize the file size of your slideshows:

Select one or more pictures in a file.
On Picture toolbar, click "Compress Picture" icon.
Select options you want.
Note: If you don't see the picture toolbar, click View > Toolbars > Picture.

NB: 96 dpi is a relatively low resolution, and while some images still render well at this dpi (and you should use 72-96 dpi for web-only display), others may result in poor image quality (e.g., jpgs with a lot of juxtaposed solid-color objects—Note such artwork looks better when saved as gifs when working in the 72-96 dpi range).

In Office X or newer, do Save As and click the "Options" button. You can select for individual slides or every slide, set advanced resolution parameters for dpi and width/height size, and compress graphics files using the image quality pulldown menu.

General Tips

Extensive scaling of imported images in PowerPoint (i.e., more than 10-15%) may yield bloated file size. Scale images to the appropriate size with the source program (e.g., doing so in Photoshop does reduce image file size).
Pick a resolution based on the intended use of the file (e.g., web, LCD display). Choose a lower resolution when appropriate (e.g., 72-96 dpi for web).
Use a compressible file format. For example, PICT and JPEG files can be compressed. (But beware that repeated saves may reduce image quality in these formats.)
When using a compressible format, choose the lowest image quality that will not detract from your presentation. You may have to export your slides at different resolution and image quality settings to find the best balance between file size and presentation quality (see Compress the Slideshow above).
Use a file format that uses fewer colors. For example, PNG and JPEG files can display millions of colors, while the GIF and PICT formats use only 256. Avoid 24-bit PNGs, however, as they will result in large file sizes.
If your slides are designed with few photographs and large areas of the same color, GIF file format will provide the smallest file size without compromising image quality.
Remember that you can save individual slides. If your presentation contains a few slides that require higher quality or more colors, save them with different settings than the rest of your presentation. This can reduce the overall size of your presentation when stored on your hard disk or removable media.