With its multimedia capabilities, PowerPoint files can blow out to massive sizes if you’re not careful. Since large file sizes can impact how your PowerPoint is read on other devices or displayed onscreen, it’s important to keep sizes as small as possible, particularly when you intend to share or present your PowerPoint to others. Let’s look at five easy methods for compressing the size of your PowerPoint file and hopefully make things easier for presentation.
1. Change file extension to zip (PC only)
Once you’ve saved your slideshow (and potentially a second copy, just in case) change the extension from .ppt or .pptx to .zip. Your computer will then warn: “If you change a filename extension, the file might become unusable. Are you sure you want to change it?” Hit ‘Yes’ and your file will become a compressed/zipped folder.
While this hasn’t reduced the file size, it does give you access to various options for compressing or editing elements within your PowerPoint. Which leads us into the next option…
2. Compress images
Following on the previous steps, open your zipped folder and you’ll see three file folders: _rels, docProps, and ppt. Open ppt, then media.
This will show you all the media used within the PowerPoint file. From here, you can reopen images in a different program for editing or compression.
You can also compress images while working in PowerPoint. Hit the ‘Picture Format’ tab, then ‘Compress Pictures’, and then choose either a single image by checking ‘Apply only to this picture’ or all images within the PowerPoint (by unchecking ‘Apply only to this picture’. PowerPoint then offers a range of resolutions depending on your required fidelity. Remember, print should be at least 300 ppi and web should be at least 180 ppi (which is minimum for retina display on most smartphones).
You can also delete crops on images from ‘Compress Pictures’; however, be wary of any image that you’ve cropped and then copied. Checking ‘Delete cropped areas of pictures’ when compressing all images will create individual copies for each image, which could take up more memory.
Compressing images can also be done prior to designing. This means every image you import into your slideshow will be automatically compressed to the resolution you set. To do this, hit ‘File, then ‘Options’, then ‘Advanced’, and in the list of ‘Image Size and Quality’ choose the file on which you want to limit image compression, and ensure you’ve unchecked ‘Do not compress images in file’ and choose from the default resolutions.
3. Compress media
Unfortunately, unlike images, there is no compress video or audio tab. The easiest way is to hit the ‘File’ tab, then ‘Info’, and then in the Multimedia (or Media Size and Performance) select ‘Compress media’. You’ll be offered pre-set quality numbers and shown if there are any trimmed or cropped areas in your video or audio. Fortunately, this option also allows you to compress a single media file or all media files in your slideshow.
For example, I used both methods to compress a 19-slide (2.5 minute) video that included animation, background music, voice over, and subtitles (total size 44MB). Compressing media to 720p HD reduced the file size to 11MB, while optimising media files reduced the file size to 12MB – both methods reduced the file size to a quarter of the original.
Compress Media (720p):
Optimise Media (21 files):
4. Convert charts to images
If you have embedded objects like Excel charts, converting them into images can help reduce your file size. First select your excel chart or object, then hit the Drawing Tools Format tab, select Group and then Ungroup. You’ll get a dialog box asking if you want to convert the object to a PowerPoint object.
Alternatively, you can cut the object and copy it back onto the slide as a picture. Simply select the embedded chart or object, hit CTLR + X to cut it, click the Home tab, hit the arrow below Paste to display a drop-down menu and select Paste Special, select your preferred image type and click OK.
However, sometimes this method may increase your file size depending on the complexity of your graphs or charts. For example, I created a PowerPoint with an Excel bar graph of 3 x 8 fields. I then copied and pasted the chart as a picture, saved it as a JPG image, and saved it as a PNG image. While the image files meant the data was inalterable, the original file was still the smallest of the four versions yet packed with the most capacity to continue creating and editing.
Paste as Picture (104KB)
JPG Image (84KB)
PNG Image (104KB)
5. Unembed fonts
Embedded fonts are saved into the PowerPoint file, so ensuring your fonts aren’t embedded will reduce the size of your slideshow.
You can also reduce the file size by turning your custom font characters into shapes. This means you can still share your PowerPoint without the receiver complaining about needing to download missing fonts, however it will also mean they can’t edit text directly.
First add a text box and select the font/text you wish to turn into a shape. Then draw a rectangle that covers the icon and remove the outline. Then right click the rectangle and hit ‘Send Back’. Now select both elements (text and rectangle), hit the ‘Format’ tab, then ‘Merge Shapes’, followed by ‘Intersect’. BOOM! Your icon is ready and no need to embed fonts.
Explore these techniques and more in our Ultimate Guide to Reducing PowerPoint Files. Download the complete and free eBook here.