Introducing the Zip trick to reduce PowerPoint file sizes

PowerPoint files can be huge, and this can be a problem – for example if you are hoping to email the file some servers have size limits for attachments. There is a simple trick (thanks to Echo Swinford for the knowledge) using Zip to investigate what might be causing the problem. Let’s look at the process:

1. First, make a copy of the file

In File Explorer, select the PPT and Control-C, Control-V in the same folder.

2. Right-click on the copy and select Rename 

3. Add the extenstion “.zip” to the very end of the file name

Make sure to put the .zip after the existing file extension (.pptx) – do not replace it. The file now becomes a zipped folder. It’should read “”

A zipped PowerPoint presentation in a folder

A zipped PowerPoint presentation

4. Now Unzip the folder to access the contents

5. Click the folder “ppt” > “media”

In the media folder you will see a list of all the image files in your presentation – jpegs, gifs, MP4s etc. Sort by Size or Compressed size, so you can see the largest easily.

Images in the Zip folder

Images in the Zip folder

6. Change view to large icons, or double click on the images, to identify them

Once you’ve identified which images are pushing up the MB count, go into your original presentation and reduce the file size for each image in PowerPoint. Select the image and in the Picture Format tab click on Compress Pictures.

compress images within PowerPoint

Compress images within PowerPoint

Choose “Apply only to this picture” to keep a better control of image quality throughout. Of course you can choose to compress all the pictures but sometimes the PowerPoint compression tool can give a low quality result.

You can also delete the cropped areas of the pictures. The tool here gives a guide on recommended resolutions – we go for 150 ppi if a small file size is crucial.

Obviously you can also use PhotoShop to really keep control on image quality and size.

7. Resave your presentation and check the reduced file size

Spot the difference.

Zip to reduce file size

Hey presto my file is no longer massive

So that’s how you use Zip to reduce the file size in PowerPoint!

Now you can delete the Zip folder and you’re done!

For more advice on how to reduce file size in PowerPoint, there are plenty of How To videos on YouTube, like this one.

The Zip-less route

And if all that seems a bit too fidlly and faffy… you could try using an Add-in for PowerPoint to identify those large media files instead.

Slidewise is one Add-In that lets you find large images without leaving PowerPoint. The image identity feature is free.
Or there’s BrightSlide too from Bright Carbon, and i-Slide as well.


Frequently Asked Questions:

1. Why should I reduce the size of my PowerPoint files?

Answer: Large PowerPoint files can pose problems when sharing via email or uploading to servers with size restrictions for attachments. Reducing file size helps in smoother sharing and distribution.

2. What is the “Zip trick” mentioned in the text?

Answer: The “Zip trick” involves making a copy of the PowerPoint file, renaming the copy with a “.zip” extension, and then unzipping the folder to access its contents. This allows users to identify large media files, such as images, within the presentation and take steps to reduce their size, ultimately reducing the overall file size.

3. Are there alternative methods to reduce PowerPoint file size besides the Zip trick?

Answer: Yes, besides the Zip trick, users can utilize PowerPoint’s built-in compression tools to reduce the size of images within the presentation. Additionally, there are add-ins available, such as Slidewise, BrightSlide, and i-Slide, which can help identify and manage large media files within PowerPoint presentations.

Don’t want to waste hours fiddling with the technical aspects of PowerPoint?

Leave it to the experts!

We know the ins and outs of the ever-changing software, and can create interactive, engaging presentations using the most advanced options.

Let’s face it, we all have an extensive to-do list, without having to get to grips with ever-changing software!