Reducing PowerPoint file size with retina images I am using PowerPoint from Microsoft Office 2016. I use a lot of screenshots (save the screenshot to clipboard and paste it in PowerPoint). When using the retina display, the presentation file size becomes a lot bigger compared to the same task using a normal display. That makes sense, since the same size images would be 4X as many pixels.

There seems to be a solution. You can go to File > Compress Pictures. However, I don't think that compresses the images properly. I can set the resolution to a very low setting. That makes the images very blurry and the file size is reduced. However, the file size it still much higher than using non-retina images without any compression. The non-retina presentation is smaller file and better quality in the end. I think that the way PowerPoint calculates the resolution, that still somehow does not take into account the retina conversion by the OS.

Is there a way to use PowerPoint with a retina display, but still keep the images to a reasonable size? Can I keep PowerPoint in non-retina mode somehow?

Looking at previous posts, there used to be an option to "Open in low resolution" in File > Get Info, but that does not seem to exist anymore.
Try saving the screenshots to a JPG file and then inserting them into the Powerpoint. You can switch the format that Mac OS saves screenshots in to JPG by typing the following command into a terminal window:

defaults write com.apple.screencapture type jpg;killall SystemUIServer


I just tried it with identical screen shots and saving to a JPG file and then inserting into the Powerpoint made the file 80% smaller than pasting the screen shot directly into the Powerpoint. The quality was identical.



You can shrink your existing files by saving the screenshots out of Powerpoint as a JPG (right click and choose save as picture), then delete it from the slide and re-add it from the JPG you saved. 

To switch back to saving screenshots as PNG, use this command:

defaults write com.apple.screencapture type png;killall SystemUIServer