How to compress PowerPoint presentations and reduce picture file size

Media-rich presentations are great. Including high-quality images and videos often adds hugely to audience engagement, but it also adds file size. Adding to your file size means that your presentation is likely to sit on the unfriendly size of email etiquette, but it also means your PowerPoint will run a lot slower (and it may crash – see this article for more on that). But is there an answer? Absolutely. Here are five ways to compress PowerPoint file size for easy emailing and speedy running of your presentation.

View our tips in this video.

The content from the video can be found in the article below.

Method 1: Compress PowerPoint presentations using in-built tools

Did you know PowerPoint has a built-in picture and video compression tool? Well it does, and it’s really easy to use.

Images:

1. Select a picture on any slide and go to the Picture Tools Format tab on the ribbon.
2. Choose Compress Pictures in the top left corner: the pop-up box shows you the resolution options you have for the image. For most purposes the web resolution of 150ppi is fine, but if it’s a particularly large screen you’re using, or you’re going to print it, maybe choose the print 220ppi option. This reduces the resolution of the image down to that level, which should help reduce the file size of the image a bit.
3. If you uncheck the first box, you’ll apply that resolution change to all of the images in the deck, pushing the file size down further.
4. It’s interesting to note that if you crop an image in PowerPoint, the cropped portion of the image is still there, just hidden away. That also adds to the file size of the PowerPoint, so checking the second box will delete any of these hidden areas, potentially reducing your file size quite a bit more.

Videos:

1. Navigate to the File tab in PowerPoint, and the Info page should be selected.
2. If you have video files in your PowerPoint the first button on this page will be to ‘Compress Media’. Click this button and choose the quality you want PowerPoint to compress your file to. 1080p is fine for almost any application, and in many instances 720p will work well too.
3. Once you’ve chosen a video resolution, you’ll see a new window open showing the progress of the compression. It’ll also tell you how much space has been saved after the compression has been completed – handy.
4. Check your video after it’s compressed to make sure it still looks good. If you realise you’ve made a terrible mistake, you can also undo the last compression from the same ‘Compress Media’ drop-down menu.

That may do the trick, but sometimes you’ll come across a presentation that stubbornly refuses to yield a decent file size. At this point, you need to get tricksy.

Method 2: Locating large files in your PowerPoint

A problem you can face when you need to compress PowerPoint slides is that, often, you don’t know which object is causing your file size to jump so much. It might be that 90% of your media files are a combined total of 5MB, but there’s one troublesome image that is 30MB on its own. Here’s a fool-proof way of finding which files are causing you problems.

1. Go to the folder where the presentation is stored. You can see the file size in the bottom left corner. Go to the view tab at the top and select the File name extensions box over on the right-hand side. This puts the file type extension at the end of all your files, so for PowerPoint, it’s .pptx.
2. Now, copy and paste your PowerPoint file, using Ctrl + C and Ctrl + V. On the copy of the file, click on the .pptx and change it to .zip. Windows will give you a warning that you could ruin your file, but that’s OK, because this is a copy and the original is still safe. Say yes, and then you’ll see that your PowerPoint file has now turned into a zip file.
3. Open the zip file and you’ll be greeted with a lot of unfriendly looking folders. Go into the ppt folder and there are even more unfriendly folders. Then go into the media folder, and here you’ll find all the images, music, and video files used in your presentation. At this point, you can sort them by file size, and easily see the culprits that are jacking up your storage allocation.
4. Once you’ve got them, you have a couple of options. You could go into an image editing program, and the Photos app in Windows 10 is actually really good for this. Simply open an image, go to the dots menu on the right-hand side, choose Resize, and then adjust the resolution of the images easily. In most presentations you can take this down to the 2MP setting, or define custom dimensions, with the smallest side around 1000 pixels.
5. A neat way of actually finding the large image within the deck is to delete the large image in the zip file and change it back to a .pptx from a .zip. When you open it up in PowerPoint your picture will have been replaced by a white box with a red cross in it. Right click on the white box, choose Change Picture, and find a different, or a lower resolution image to fill the gap.

For video you’ll likely need to use another tool, so find the video files using the zip method, or extract them using the free BrightSlide PowerPoint add-in (File & Master > Export Media Files), and then use the methods below with the free Handbrake video editing software.

Method 3: Reducing picture resolution in PowerPoint

1. In PowerPoint, find the image that’s huge (using method 2), copy it, and reduce the size of it physically on the slide.
2. Copy the new smaller image using Ctrl + C, and then paste it using Ctrl + V. Before doing anything else, you’ll see there’s a little pop-up box in the bottom right of the image, which are the paste options. Choose the ‘Picture’ option and your image is now a new picture at a lower resolution (because you made it smaller on the slide). Then use this to replace your existing image, which will cut out the large file size version.
3. If you’ve got lots of animation on your image or it’s in a group and you don’t want to have to redo it, right click on the new smaller image, choose Save as Picture, and save it somewhere.
4. Right click on the original picture, and choose Change Picture, which allows you to find another image to replace it with. If you choose the image that you’ve just saved, you shouldn’t see any difference on the slide, but your old large file size image should now have been replaced with the lower resolution, smaller file size image, helping to reduce the file size of your presentation.

Method 4: Use the correct file types

Another tip is to think about the type of image file you’re working with. The three most common are JPEGs, PNGs, and TIFs. JPEGs are the most common. They’re usually slightly lower quality, but it’s often difficult to tell, unless the screen is really good or very large. PNGs provide excellent quality for the size, and also allow you to have transparent areas of your images, but that comes at a cost, with file size usually pretty high. TIF files are often produced by high quality cameras in professional photo shoots. They’re great for print, but overkill in a PowerPoint presentation. So if you’re struggling with the file size on a particular image, try saving it as a JPEG:

1. In PowerPoint right click your image and choose Save as Picture.
2. Choose JPEG from the Save as type drop-down options in the window that opens up.

Method 5: Streamline your PowerPoint file by deleting things you don’t need

The last way to keep your file size low is to make sure you don’t have anything in the file that you don’t actually need. What might this be? Well, it’s things like huge Slide Masters and templates with images and graphics on them that you just won’t ever use. To streamline your PowerPoint file:

1. Open the ‘View’ tab in the PowerPoint ribbon and select ‘Slide Master’.
2. If you can see a number of masters that don’t appear in your presentation, then delete them.
3. If your template uses a lot of images, and you can’t delete them, then use one of the other methods to compress them to save a little space.

Tip 1: Always ‘Save As’ – you might not need those layouts this time, but you might need them in the future.

Tip 2: If you have a number of layouts you don’t use then it might be worth chatting to the team that put the template together to see if they can reduce the number of slides in the interests of keeping file size low.

And all of these tips combined will help you to compress PowerPoint files, resulting in svelte slide decks that you can use and share with ease!

How to reduce video file size with HandBrake

If you want fine detail control over resolution or codecs, or want to remove parts of the video, you’ll need to use a specialist video tool. A terrific one is HandBrake, a free, excellent quality video transcoder that possibly has the best logo and program icon ever. You can use HandBrake to change the format, codec, resolution, frame rate, and bitrate, plus loads more. If that sounds a bit technical, sorry, but the presets are really good. Drag the video file you want to compress into Handbrake, and in the Presets drop-down menu in the top left, choose either Fast 1080p30 or Fast 720p30 (that’s 1080p resolution at 30 frames per second), and then the green Start Encode button at the top. This will often magically reduce file size by up to half, and it takes only a few minutes.

If you’re really keen, you can use the Range options at the top to trim the video, removing a lot of unwanted footage. This is essentially the same as the trimming function in PowerPoint, but you immediately remove all the footage from the video, rather than having to use the compress media function. You may want to do this if you want to keep the resolution of your video, and it’s larger than the highest 1080p resolution available with compress media, such as 4K.

It may also be useful to use HandBrake to convert the format of a video not playing in PowerPoint. My colleague John has written a nice overview of how to do this and what else you can do if embedded videos in PowerPoint aren’t playing, and there’s a good test file to see what might be causing the problem on your computer.