How to compress images in PowerPoint

Using images in high definition is essential to create a quality presentation but the images take up more memory and weight your PowerPoint, with the result that you can no longer send the presentation by email and you have to send it via sites such as WeTransfer.

In PowerPoint there is the possibility of compressing the images: reducing the resolution.

Before showing the technique, a small note to pay attention: size and place the images before compressing them, because if you compress them and then enlarge them, for example, with a full slide, as we did before, you risk getting an image granulated.

Then, you found an image in high definition, you imported it into PowerPoint or you entered it directly through MLC PowerPoint Addin, you have already redesigned, re-provided and expanded to full page and you are ready to compress it.

Select the image and open the format menu or double-click on the image. Inside the format menu is the “Compress Pictures” button that opens a functional window for the compression of the images in the presentation.

Within the window you will find two main sections:

Compression options

“Applying only to this image” is a phenomenal command because it allows you, if not selected, to apply compression to all the images in the presentation.

This button is marked by default to avoid unintentionally compressing all the images, but, in my opinion, it is sensational to deselect and compress all the images together in one step.

Flag the “Delete cropped areas of images” checkbox to remove areas outside the image cropping frame.

If you think, the cropped area are parts of images that you have decided not to show in the presentation but that remain masked in your PowerPoint to occupy the memory unnecessarily.

Just be careful that once you have removed the cropped area using the compression function, you will not be able to recover it.


The resolution of the real image. Obviously, the lower the resolution, the better the compression will be and the lower the quality of the image.

At this point, however, you should know that the difference is the fate of the image. In fact, we don’t use higher resolutions to print the images.

In general, since you project PowerPoint presentations, on screen, you can work with lower resolutions.

My advice is to stay at 150 ppi as much as you can, and if you need to compress the space in excess, up to 96 ppi.

Where are the PowerPoint images really located?

Despite the compression, the PowerPoint file continues to weigh heavily. There might be an image that can’t be compressed beyond a certain threshold and that you’d better consider replacing it.

How do you identify which image is creating the problem? You can not just scroll through the slides because you do not have indicators in PowerPoint to understand the weight of the images.

To answer this question, you must learn to unzip a PowerPoint file, examine it, and analyze in detail all the images it brings.

Actually, it is a simple and effective technique and the first time you do it will open a new world for you.

I will give you an example with the PowerPoint file that I am using to compose all the graphics in this article.

The technique is to change the file extension from “pptx” to “zip”. I have created a copy of the file to do the example because I have the PowerPoint open, but it is not necessary to do so.

Open the zip file (you must have installed a tool to open the files, I use winrar). Now you will see your PowerPoint file in a way that you have never seen it … naked!

This is the content of a pptx file.

Where are the images? Follow me, I will show you.

Enter “ppt”

Now enter “media” and here you will find all the images contained in the presentation

As you can see, from here, it is very easy to identify how much each image weighs and which one is the least.

To return to the presentation, simply change the file extension from “zip” to “pptx” and then open the PowerPoint file normally.


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