First, open your PowerPoint file and use File > Save as. Save the file with a different name. Close everything and open the new file which should be at least a bit smaller.
If you’re using a PC, please try the following:
In PowerPoint 2010, under the File tab, click ‘Info” and select the option to Compress Media.
On a Mac, the only way to decrease the size of the audio used in a PowerPoint presentation is to record it in another program at a lower quality. Audacity is a free and easy to use audio recording/editing application that we recommend using. You can get the latest version for Mac OS X 10.4 or later at
As well, you should download and install the LAME mp3 encoder using the instructions for Mac OS X at
Once you have Audacity and the LAME mp3 encoder installed you can record your narration for each slide individually. As you finish recording each slide’s narration, you will need to save it as an mp3 file by doing the following:
- Go to File > Export
- Choose mp3 from the “Save as Type” drop-down box
- Click the “Options” button
- Set the bit rate to 96kbps or 64kbps
- Name the file and choose the location to save it in
Once you file is saved as a lower quality mp3, you can then import it in to the PowerPoint slide that it belongs to.
If you require further assistance using Audacity, you can look over their “Documentation and Support” page at
for links to Manuals, Wikis, and Tutorials. There are also some great How-to videos on YouTube.
After completing all the steps provided, if your file is still more than 50Mb, please break your file into two parts by doing the following:
- Make a second copy of your presentation
- Delete the slides that you do not want from the end of the current copy of the presentation
- Save it and add “Part 1” to the file name
- Open the second copy of your presentation
- Delete the slides from the beginning of it that are in the “Part 1” file
- Save it and add “Part 2” to the file name
- Upload the first part with your first post; noting in the post that the second half will be posted.
- Remember that you must include a subject as well as message for the post to work.
- Then post a reply with the second part.
For Older Versions
There are some tips to make PowerPoint presentations smaller available at