File size not changing when compressing

Most of your presentation may be images, and images are already compressed (jpeg, png, etc...), so attempting to compress them again will either have no effect, or could actually result in more storage being taken for some images.

I recommend using the Powerpoint option to reduce the size of the application.

This will remove unnecessary image excess and delete cropped areas (see below):

This is the best way to reduce PowerPoint file size.

Cheers,

LM

That's possible.

See if this helps: Reduce the file size of your PowerPoint presentations