How to Reduce Image Size in Outlook (Web and Classic Outlook)

In Outlook on the web, add the photo to your message, right-click its attachment card and choose Move image to the message body. In my test, Outlook kept a much smaller copy inline. Then use Picture format > Size to make it look smaller.

In this tutorial, I’ll show you how to reduce image size in Outlook on the web, what the Size menu really changes, and what to do in classic Outlook or when a photo is still too big.

Shrink a big photo by moving it into the message body

I tested this with a real phone photo for my made-up business, Bluebird Landscaping Co. The file, Oak Street patio install 2026.jpg, was 4032 x 3024 pixels and 4.5 MB on my computer.

When I added it to a new message, it landed as an attachment card that said 4 MB. Right-click that card and you get Preview, Copy, Move image to the message body, Upload to OneDrive, Download and Remove attachment.

Click Move image to the message body. In my test, the inline picture Outlook kept was 1920 x 1440 pixels and just 365 KB. That’s where the real file-size drop came from.

Big attachments add up fast in a mailbox. If yours feels full, here’s how to check your storage space in Outlook.

Make the picture look smaller with Picture format > Size

Click the picture in the message body and a Picture format tab appears on the ribbon. It has Picture border, Shadow, Crop, Size, Rotate, Change picture and Alt text.

Open Size and pick Best fit, Small (25%), Medium (50%) or Full size (100%). I picked Small (25%), and the photo showed at 480 x 360 pixels.

Here’s the catch: Size only changes how big the picture looks. The stored image stayed 1920 x 1440 and 365 KB. Microsoft’s help says the same about the Size menu in new Outlook for Windows: it changes the display size, not the file size.

While you’re writing, a quick font change in Outlook Online can make the message easier to read too.

What the recipient sees

I sent the message to myself to check. The received email showed the photo at the small size, right under “Hi Dana, here’s the finished patio at Oak Street.”

The image inside that received email was still 1920 x 1440 and 365 KB. So the recipient still gets a sharp 1920 x 1440 photo, while the message itself stays light.

Want to find the heavy messages you already have? Sort your emails by size and the big ones jump to the top.

Reduce image size in classic Outlook for Windows

Classic Outlook has two options Microsoft documents that actually shrink the file, not just the view.

• Resize when you send. Attach the images, go to File > Info, and under Image Attachments select Resize large images when I send this message. Then go back and click Send.
• Compress Pictures. Select a picture in the body, then on the Format tab, in the Adjust group, click Compress Pictures. It keeps the height and width but lowers the resolution. Web (150 ppi) is the usual pick for pictures nobody will print.

Dragging the corner handles in classic Outlook is like the Size menu on the web. It changes how big the picture looks, not the size of the email.

When the photo is still too big to send

Microsoft lists a 20 MB limit for Outlook.com and a default 10 MB limit for Exchange business email. That limit covers the attachments and the message together.

For a whole set of job-site photos, upload them to OneDrive, copy the link and paste it into your email. You can also save Outlook emails to OneDrive to keep a copy there.

Zipping the files into one compressed folder before you attach it is another option Microsoft suggests.

More Outlook Online fixes from my mailbox

• Add stock images in Outlook Online
• Download an Outlook email
• Set a calendar reminder in Outlook
• All Outlook Online tutorials

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