I have a 10-slide presentation that is a whopping 234 MB!

This is because each of its slides has a different high-resolution image as its background.

(I know that the large filesize is due to these photos because I tested this by temporarily setting all slide backgrounds to a solid color, and the file size dropped to 1.5 MB.)

I've already tried the "Compress Pictures" feature mentioned here, but it seems not to affect background images.

I've searched all over the internet and have only found articles mentioning that approach and never mentioning the resolution of background images.

I'd really rather not need to manually resize large photos every time I'm about to use one as a slide background in Powerpoint.

UPDATE about why I care about this:

I think my Powerpoint presentations are the most beautiful I've ever seen because each slide has a different gorgeous photo as its background (with its brightness dimmed 40% so that white text is readable).

But these files are so big that my computer has difficulty running Powerpoint (even though I have a blazing fast new system with lots of RAM). Plus, I more quickly run out of local disk space or online storage space if the files are enormous.

  • @Firee I updated my question to explain why enormous file sizes are unacceptable. (And wouldn't everyone always prefer smaller files, though?) Thanks.
    – Ryan
    Jul 2, 2016 at 2:48

3 Answers 3


Ok here's how you do it. Drop an image in to one of the slides and then perform the "Compress Image" feature. When you do, deselect the checkbox that applies it to only that image. Run it. Then all images in the entire deck will be optimized, including the background images. I just did it and it made the 96m file 26m.


Hm, that's a good question. Have you tried placing the image on a slide master (instead of the slide background) and then compressing images?

Otherwise, what I would do is first place the full image (how you want it to appear) on your slide, then compress all images in your deck, and only then make the image your slide background. That should do it.

  • 1
    This does not really answer the propose question. Please leave comments to questions to the comment section
    – Ramhound
    Feb 3, 2016 at 20:13
  • I know but I just joined and don't have enough reputation to post a comment yet...Could someone copy/paste it into a comment then and then just delete my answer then?
    – Camille
    Feb 4, 2016 at 20:53
  • 1
    Actually, it answers the question nicely. You can compress all images in the deck or just the one you want to apply to the background. Once it's compressed, you can copy it, rightclick off the slide, choose Format Background, Picture or Texture Fill then Insert Picture From Clipboard. Delete the original image and you're good to go. Feb 13, 2016 at 2:36
  • @Camille and Steve, I updated my question to more clearly explain that the background images on my Powerpoint slides are each different photos. So I don't believe that editing a Slide Master could help me. Thanks though. I'm definitely eager to hear other ideas.
    – Ryan
    Jul 2, 2016 at 2:49

I had kind of the same problem. You can right-click in the background and then save image. Then using a external software (my case as it was simply changing from PNG to JPG, MsPaint). And then you add to the background again the new compressed picture.

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