PowerPoint files can be quite big. Not that it matters too much, now that we have huge amounts of local and cloud storage available, and even email quotas tend to allow large message sizes, so your 25MB PowerPoint file will typically still get through.

What lots of people do when they’re building a new PowerPoint deck, is to start with a template they like – a conference slide deck, or a jazzy marketing one they got a copy of. They delete the slides they don’t need, and maybe create a few of their own, and there’s a beautiful new document, ready to use.

As the decks morph in these ways, lots of hidden stuff stays embedded, even when it’s not used. In a recent group exercise, a bunch of people were asked to create a business plan deck for every one of hundreds of accounts, but the template they were asked to use was nearly 10MB in size before there was any real content within.

In this case, the reason was that the slide deck had over 200 master slide layouts within the template, many of which had large embedded bitmap images. If you find a slide deck whose file size is huge even if there isn’t much content in the slides themselves, you may see the same behaviour. ToW #276, some 4 years ago, covered a few things you can do to make the file smaller, but here’s a slightly more straightforward solution.

In your huge yet seemingly empty file, try going into the View tab in PowerPoint and look under the Slide Master view. You’ll see a vertical list of thumbnails for all the different slide layouts (where each contains background graphics as well as layout controls).

Hover over each thumbnail, and a tool-tip will tell you if that layout is used (and on which slides in your deck). If it’s not being used… then maybe you could ditch it and save some space?

A simpler way than deleting all the unwanted layouts – if there are many – would be to create a new, blank PowerPoint, then (back in the normal slide sorter view, rather than slide master), copy the slides from the the huge slide deck, and simply paste them into the new, blank file. You may want to force it to Keep Source Formatting – but this process will copy only the used slide layouts into the new deck.

In this example, copying the slides to a new deck and saving that, reduced the size from nearly 10MB to only 750KB.