How do I reduce the size of images in my Canvas course?

Using images that are bigger than they need to be can make your course take longer to load, negatively affecting students with slower or limited internet connections.

You can resize images in Canvas when adding them, but it only appears as though they are resized – in fact, they remain the same size. Using images that are bigger than they need to be can make your course take longer to load, so to accommodate students with slower internet connections it is best to resize large image files before adding them to Canvas.

We recommend doing this using Snagit, a University-supplied program that can do everyday image editing. Snagit is available through the IDS Support Portal. If you regularly work on a non-Flinders computer, home-use licences are also available.

Resizing an image in Snagit

Source your images first (as above). You may find it helpful to store them in a folder before uploading to your course, so they are easy to find later on.
Go to the File menu and select Open. You can then find the file on your computer.
On the centre-bottom of Snagit, you will see the measurements of your image. Click on the measurements to edit them.

What do the numbers mean?
The numbers refer to pixels (or px for short). A pixel is a single dot on your computer's screen. For reference, most desktop computers are 1920 pixels wide, and laptops are generally either 1920 or 1366 pixels wide. The following image shows measurements of 100 pixels.
Once you have settled on a size, save your image (go back to the File menu, and select Save).

What is an ideal file size?

The ideal file size depends on the image. For example, if you have an image of the human brain, the image will need to be big enough so students can easily identify its various parts. This, in turn, will probably make the file size larger. But if your image is only for decoration it can be smaller, as the teaching materials you've provided are the main focus.

It's good to remember that some students will have dramatically slower internet speeds than we enjoy on campus. While images definitely have an important role to play in education, it does need to be weighed against the needs of our students in remote Australia and developing countries.

If you have a jpg file (typically used for photographs) and are finding that the image size is still too large, you can reduce the quality of the file:

Go to the File menu and select Save As.
Make sure that the Save as type is set to 'JPG [1], then click on the Options button [2] at the bottom of the window.
Try reducing the image quality to 60, and then increase it to 70 or 80 if you find it is too blocky (here is an example of a blocky picture). Higher quality/larger images generally can have a lower quality than smaller or previously edited pictures.