How to compress picture file sizes in Microsoft PowerPoint (2007 and 2010) presentations

By Sean McManus

NEW: Check out my new book 100 Top Tips: Microsoft Excel!

PowerPoint is a great application for creating presentations, and in my book Microsoft Office for the Older and Wiser, I show you how it can be used to create a photo album.

But one problem with PowerPoint presentations is that they can have huge file sizes, especially if you've used lots of photos or other pictures. This becomes a problem when you want to share your PowerPoint presentation by email or publish it online, because it can take a long time to copy across the internet, and your email program might not be able to handle huge attachments.

What happens if you zip a PowerPoint file using Winzip or by right-clicking on the file in Windows 7 and then clicking 'Send to' and choosing a compressed folder? Often, not much! The file size usually shrinks a bit, but not enough to make a huge difference.

There is a way you can compress a PowerPoint presentation from within PowerPoint itself using Microsoft Office 2007 or 2010. This method is often much more effective than zipping the file.

How to compress a PowerPoint file and its pictures

Here's the step by step process to follow to shrink the size of your PowerPoint file (see also annotated illustration below):

1. Finish creating your PowerPoint presentation.
2. Click on one of your pictures. The Format tab will appear on the ribbon at the top.
3. Click the Format tab.
4. On the left of the ribbon, click Compress Pictures.
5. In PowerPoint 2007, you need to click the Options button. The Compression Settings window will then appear. In PowerPoint 2010, the Compression Settings window appears straight away.
6. In the Compression Settings, tick the boxes to delete cropped areas of pictures and select the target output to be email.
7. Click OK in the Compression Settings.
8. In PowerPoint 2007 only, you also need to click OK on the Compress Pictures window.
9. The way PowerPoint compresses your file is by deleting bits that aren't shown on screen (the bits that are cropped), and by reducing the picture quality to a level that is adequate for the screen. You might want to keep a version of your file with its original picture quality, so I recommend saving with a different name now and keeping your full size file intact.

When you compare the file sizes, you should see that the new file is significantly smaller than the zipped version. That's because when you compress a file by zipping it, you keep all the information but store it in a different way so that the file size is smaller. When you compress pictures in PowerPoint, you actually delete unnecessary information from the file, which can have a dramatic effect on your file size.

Find out more about Microsoft Office

My book Microsoft Office for the Older and Wiser is out now. Through a series of projects, it shows you how to make the most of Word, Excel, PowerPoint and OneNote. You'll learn how to design letters, posters and newsletters; how to work out your holiday budgets and manage your address book with Excel; how to create a photo album with PowerPoint; and how to keep a recipe book using OneNote. There's a bonus chapter showing you how you can use email to keep in touch with friends, too. Find out more about Microsoft Office for the Older and Wiser.

Update: This book is now out of print and the rights have reverted to me. Copies are still available to buy, and you may find you can borrow it from your local library. If you are interested in Microsoft Excel, I recommend my new book, 100 Top Tips: Microsoft Excel.