I can’t count the number of times I’ve seen someone work hard on an ambitious presentation, test it all out, copy it to a laptop, and then have it fail when presenting. The reason is usually that the the presentation has become huge and the laptop isn’t fast enough or doesn’t have enough memory to handle it.
The first message is: Always test your presentation on the computer that you’ll be presenting from.
The second message is that you should do everything you can to make your presentation file as small as possible. Here are some tips:
The number one cause of large presentations is large image files. Many people insert photographs taken at high resolution that are over 1 MB each. The best solution is to create the images at lower resolution, but when you don’t have that choice, here are some options:
- Reduce the size of the image. You can do this in PowerPoint, but you’ll have more options in an image editing program. In Adobe Photoshop, choose Image > Image Size. If you want the image to be the size of a typical slide, change the width to 10, with the Constrain Proportions check box checked. In many cases (such as a photo from a digital camera), the height will change to 7.5, just what you want to cover the slide.
- Crop the image. In PowerPoint 2007, 2010, and 2013, go to Format tab> Size group> Crop. In PowerPoint 2003, select the image and choose Crop on the Picture toolbar.
- Compress the image. (n PowerPoint 2007, 2010, and 2013, go to Format tab> Adjust group> Compress Pictures, and click the Options button. Click OK. In PowerPoint 2003, select any image to display the Picture toolbar. Click the Compress Pictures button. In the Compress Pictures dialog box, compress the selected image or all images, choose a resolution (use Web/Screen for the smallest size), and also choose to delete the cropped area of images — so you can’t restore the image to its original size. In all versions, then save the presentation under a new name — just in case you don’t like the results. I took a PowerPoint presentation with one BMP file and reduced it from 4,561 KB to 831 KB this way.
- Reduce quality (JPEG images). In Photoshop, choose File> Save As and choose JPEG as the file type. Then you can use the Quality text box or drop-down list. In Photoshop, choose File > Save For Web. By choosing Medium, I changed my photo from 41 KB to 15 KB!
- Convert the image file type. The image file type makes a huge difference. In my tests of a photo, JPEG files were the smallest by far. (GIF files are also small, but are not suitable for most photographs because they don’t support enough colors.) I took an image and Microsoft Office Picture Manager to convert it. Then I inserted each one into a different presentation, so each presentation had one slide with one image. Here are the results:
|Image size (KB)||Presentation size (KB)|
- Convert embedded graphics to PowerPoint objects. If you used Insert> Object to embed an object, it’s hard to tell what may be in that image (or charts or spreadsheet). Try to ungroup it (right-click it and choose Grouping> Ungroup). Then regroup it again. Note that you won’t be able to edit the object with the original program, so save the presentation under a different file name, just in case.
- Don’t copy and paste, or drag ‘n drop, images into a presentation. Instead, save them as a separate file and insert them as a picture. If necessary, you can copy and paste into an image editing program and save the image there before inserting it into PowerPoint.
Here are some file handling tricks that can also reduce the size of a presentation:
- Save the file under a new name. PowerPoint remembers all your actions in a session so that you can undo them. Saving under another name discards this information. For some reason, this works better than closing and opening the same file.
- Disable fast saves. This feature increases file size. Choose Tools > Options. On the Save tab, deselect the Allow Fast Saves check box.
- Don’t save in PowerPoint 95 compatible format — it’s much larger.
Third party software
There are two programs that do an excellent job of compressing PowerPoint presentations:
pptMinimizer, by Balesio. This also works with Word and Excel files.
NXPowerLite. This also works with Word and Excel files.
For more ideas, see Steve Rindsberg’s “Why are my PowerPoint files so big?”