Compressing images in a document

Sometimes you or your students may need to attach a document to an email, discussion board, submission point etc. where there is a limit on the file size it can accept. The most common reason for a document to be too large is if it contains images. This article explains how to check the size of a file, and how to compress images so that the resulting file size is smaller.

Checking file size

In Windows File Explorer, right-click on the file and select ‘Properties’ at the bottom of the list. The file size will be shown in the General tab in the Properties box.

Screenshot of file properties

On a Mac, select the item and choose File > Get Info.

Compressing images

If the file size is too large, you can compress the images within the document.

In Word:

  1. Click on the picture.
  2. A new tab, Picture Tools – Format will appear at the top. Select this.
  3. Look for the ‘Compress Pictures’ icon.

Screenshot of Compress Pictures icon

Choose the settings.

Screenshot of Compress Picture options

If you want to compress all your pictures at once, untick the ‘Apply only to this picture’ box. If you have cropped your images, ‘Delete cropped areas of pictures’ will save a lot of space by removing the cropped (non-visible) areas of your images (note you won’t be able to recover any of the cropped areas once you do this). The resolution you need depends to some extent on the image and its purpose. The smaller the pixels per inch (ppi) the less detail there will be (and the smaller the resulting file size will be).

See Microsoft Support pages for more information.

For Pages on a Mac, see Apple Support pages. Other word-processors may have similar features – check their help pages online.


Photo by Polina Tankilevitch from Pexels