How to Compress Media Files in a PowerPoint Presentation to Reduce File Size

Embedding a high-resolution 4K video clip or dozens of raw DSLR photographs into a Microsoft PowerPoint presentation guarantees your slides will look stunning on a large projector. However, it also guarantees your .pptx file will quickly balloon to hundreds of megabytes in size.

Massive PowerPoint files are a nightmare to manage. They take forever to upload to cloud storage, often exceed the maximum attachment limits for email clients (typically 25MB), and can cause older laptops to lag or crash during a live presentation.

Instead of manually downscaling every image in Photoshop or running your videos through Handbrake before inserting them, you can use PowerPoint’s powerful built-in compression engine to dramatically shrink the final file size in just a few clicks.

How to Compress Embedded Videos and Audio

If you have inserted large .mp4 video files or heavy .wav audio tracks, you can compress them globally across the entire presentation.

1. Open your heavy PowerPoint presentation.
2. Click on the File tab in the top-left corner of the ribbon.
3. Select Info from the left-hand menu.
4. If your presentation contains heavy media, you will see a large button at the top labelled Compress Media. (If you do not see this button, your media files are either already heavily compressed or are linked from the web rather than embedded).
5. Click the Compress Media button to open a dropdown menu with three quality options:
   • Full HD (1080p): Best for modern projectors and large screens. Moderate file size savings.
   • HD (720p): The best balance of quality and size for most standard presentations.
   • Standard (480p): The lowest quality, resulting in the smallest possible file size. Use this if you absolutely must email the file and the visual fidelity of the video is not critical.
6. Select your desired quality. A pop-up window will appear showing the progress as PowerPoint scrubs through your slides, trims out unused video data, and re-encodes the media.
7. When finished, the window will explicitly tell you exactly how many megabytes were saved.

How to Compress Pictures

The “Compress Media” button only affects video and audio. If your presentation is bloated due to massive images, you must compress those separately.

1. Navigate to any slide and click on any image to select it.
2. The Picture Format tab will appear at the top of the ribbon. Click it.
3. In the “Adjust” group (usually on the far left), click the Compress Pictures button (an icon showing a picture with small blue arrows pointing inwards).
4. A dialogue box will appear with crucial options:
   • Apply only to this picture: Uncheck this box. If you leave it checked, PowerPoint will only compress the one image you clicked on. By unchecking it, PowerPoint will compress every image in the entire presentation.
   • Delete cropped areas of pictures: Keep this checked. If you cropped a large photo inside PowerPoint, the program secretly keeps the hidden, cropped-out areas saved in the file just in case you change your mind later. Deleting them saves massive amounts of space.
5. Under “Resolution”, select Web (150 ppi) or E-mail (96 ppi) for the best file size reductions.
6. Click OK.

Finally, click Save As to create a new copy of your presentation. You will likely find the new file is a tiny fraction of the original’s size, ready to be emailed or uploaded instantly.