Adding images to your presentation involves only a few simple steps. First click the "insert" icon at the top, center of the Prezi page, then click "Image" in the drop-down menu..
This brings up a window enabling you to add images in one of two ways. First, you can locate and select the appropriate file on your computer (upload multiple files by holding down the "control" key on a PC or the "command" key on a Mac as you click). The maximum upload size for images is 2880 by 2880 pixels. While you may be able to upload a larger image, it will cause problems while editing and presenting. Supported image formats include: JPG, PNG and GIF. Progressive or CMYK JPEGs and the JPEG2000 format are not supported.
Note that when you view your image in Prezi, the program zooms in until your image fills the screen. If your image is low resolution, this will be highly evident. You may want to put a border around your image in Photoshop or an equivalent program to make your image appear a more reasonable size.
The second option is to add an image via google search. Type in a search term and click the search button.
You will see a large photograph of the first result, and a vertical rendering of other potential images.
Move through this list by clicking towards the top or the bottom (dragging your mouse will move your workspace rather than the thumbnails) or use the "up" and "down" arrows on your keyboard. You can replace the larger image by clicking on a thumbnail, and you can finalize your decision by clicking "Insert" next to the search bar.
To move, resize, or crop your image, see this page.