Here's a little collection of PowerPoint tips I make use of when working on my own webinars and while supporting clients. These have been floating around the internet for quite some time, so I don't claim any brilliant new personal discoveries in this space. But who knows… You might trip across something you had forgotten or something that is new to you.
TIPS TO REDUCE FILE SIZE
1) Don't copy and paste images onto slides. Save images to your hard drive and use PowerPoint's "Insert Picture" command to bring them onto your slide. Once they have been inserted in this manner, you can copy/paste or duplicate them within the PowerPoint slides.
2) Save images to disk as JPG for the greatest amount of compression. TIF (or TIFF) and BMP formats are usually the largest sizes. GIF and PNG are somewhere in the middle.
3) Look for images hidden in Master Slide layouts. I often see presentations that keep getting additions with multiple master layouts. If the masters have large images, they can add to the file size without you seeing them. Once you have finalized your slides, eliminate all unused master slides. Efficiency tip: You can just starting deleting masters in sequence. PowerPoint automatically prevents you from deleting masters that are in use by slides.
4) To find the big images in your PowerPoint that are causing it to balloon in size, follow these steps:
a) Copy the PowerPoint file on your disk so you aren't working with the original.
b) Rename the file copy from PPT or PPTX to a ZIP extension. Windows will make you confirm the action. Go ahead.
c) Open the ZIP file and navigate to the ppt/media folder. Sort it in descending order of Compressed size.
d) Note any images that are larger than 1MB. There is no need for any image to be that large. You will have to open them and then look through your PowerPoint slides to see where they are in the presentation. (You can work your way down the list to smaller and smaller image sizes with correspondingly smaller gains in compression).
5) The ZIP method in (4) also shows you each image's format. If you saw that a large image had been inserted in BMP or TIF format, you can easily go back to your slide and right-click on the image. Choose "Save as Picture…" and change the save format to JPG. Then right-click the image again and choose "Change Picture…" Select the JPG you saved and it will retain the proper size and formatting. Even animations remain attached. [It may not be necessary, but before doing the save/change process I always change my view size to 100% so I know I am working with images at absolute size.]
THE NEXT STEPS SHOULD BE APPLIED TO A COPY OF THE POWERPOINT FILE. LEAVE YOUR FULL SIZE SOURCE INTACT IN CASE YOU NEED TO MAKE CHANGES.
6) Once you have finalized your presentation, look for charts, graphs, or tables linked to (generated from) live spreadsheet data. You can right-click them and save them as JPG images as well. You can't use "Change Picture" to reinsert them, so you'll have to manually insert the saved picture on the slide and delete the original. You need to do this step independently from the rest of your changes and compare file sizes before and after. Depending on the amount of data in your spreadsheet, the change to picture could decrease or increase the final file size!
7) Once you have manually swapped out the largest images, use PowerPoint's compression tool to automatically minimize everything else. Click an image and choose "Format: Compress Pictures." Uncheck "Apply only to this picture", check "Delete cropped areas" and choose Web (150 ppi) for the output size.
TIPS FOR WORKING WITH SLIDE DISPLAY IN WEB CONFERENCES
1) If your web conferencing software displays slides using screen sharing, look for animation effects and slide transitions that use movements such as Fly In/Out, Wipes, or Fades. These may not reproduce smoothly for attendees on slower networks or computers. You are safest using simple Appear/Disappear animations and no slide transition effects.
2) If your web conferencing software uses an upload/convert process to hold and display your slides, check every slide to make sure fonts are converted correctly and animation effects and slide transition effects are retained correctly. You may have to alter your slides to compensate for conversion errors or limitations.
3) If your web conference software can't show animation effects, you can simulate a sequence of builds, overlays, or disappear animations in PowerPoint. Start with the slide with all components on it. Duplicate the slide several times. Now go back and delete components from the slide on each successive copy. As you move from slide to slide, you should be able to recreate the effect of things appearing or disappearing. Don't worry about the large total number of slides you end up with… The effect and total presentation time is no different than a single slide with animations.
4) Some web conferencing products have problems converting PowerPoint SmartArt graphics. Those are highly complex and proprietary formats to PowerPoint. But once you have your slides finalized, you can right-click on the SmartArt image and choose "Convert to Shapes" (make sure to do this on a copy of the original so you can make changes to the source later if necessary). The image gets changed to standard PowerPoint graphics that your conferencing software will be able to handle.
TIPS FOR CREATING HANDOUTS OR REFERENCE NOTES
1) You can print your notes pages to a PDF document for a quick "eBook" version of your PowerPoint that shows slide graphics and speaker notes. You can also use a more complex series of steps to print just the slide notes to a text file for further editing or manipulation. I wrote an article about this with reference links all the way back in 2009. Check it out for details!
Hope you found some value and got some ideas from this list. I'd love to collect additional tips and suggestions in the Comments section. Don't be shy!