PowerPoint: The Art of Compression

We’ve all been there.

You finish your masterpiece presentation. You’ve spent hours aligning text boxes. You’ve raided Unsplash for high-resolution 4K royalty-free photos. It looks incredible.

You hit “Send” to email it to your client, and three seconds later, Outlook smacks you in the face:

“Message size exceeds limit.”

You check the file size: 350 MB.

The culprit? It’s almost always the images. You dragged and dropped 10MB raw photos into a slide that will be projected at 1080p. PowerPoint keeps that full resolution data by default, “just in case.”

The Built-in Fix

You don’t need to open Photoshop and manually resize 50 images. PowerPoint has a surprisingly capable compression tool built right into the engine.

1. Select any image in your presentation.
2. The Picture Format tab will appear in the ribbon. Click it.
3. Look for Compress Pictures (usually near the top left, icon looks like a photo with arrows squeezing it).

The Secret Menu

When you click that, you get a dialog box that determines the fate of your file size.

1. Resolution

• High fidelity: Preserves the original. Do not use this if you want to save space.
• HD (330 ppi): Good for HD displays (Retina screens).
• Print (220 ppi): The sweet spot. Excellent quality for projectors and standard screens, but drastically smaller file size.
• Web (150 ppi): Use this if you are absolutely desperate for space.

2. The Trap: “Delete Cropped Areas”

There is a checkbox labeled “Delete cropped areas of pictures”.

This is where the magic happens. If you cropped a giant photo to just show a tiny face, PowerPoint is typically still holding onto the rest of that photo in the background, in case you want to un-crop it later.

• Check it if you are 100% sure the design is final. It permanently deletes the unseen pixels, saving massive amounts of space.
• Uncheck it if you think your boss might say “can we move that image slightly to the left?” five minutes before the meeting. Once those pixels are deleted, they are gone forever.

The Result

I commonly see decks drop from 300MB to 15MB just by running this tool with “Print (220 ppi)” and deleting cropped areas.

Your email server will thank you. And so will the person downloading your deck on hotel WiFi.