One thing you'll need to remember when uploading photos to any website is that the larger the file size of your photo, the slower your page will load. Longer page load times could cause your donors to leave your donation page before it loads completely. You will want to use as small a file size as possible for your background photo to decrease your page load time. We recommend that you don't use a photo over 200kb in size. The best format to save your photo as is JPEG (.jpg).
On the other hand, any photo that is less than 1200px x 900px has the chance of being pixelated on larger screens. This is because photos must be stretched to fill the full background. This becomes even more pronounced on Retina displays, which require photos to be twice as large as usual because they pack twice as many pixels into a square inch. You'll want to use a photo with the largest dimensions possible while still keeping your file size small. In general, a good rule to follow is to use photos with a ratio of 4:3, width to height, with minimum dimensions of 1200px x 900px.
Revv is also mobile-friendly, which means that the whole website will resize itself to fit whatever size device you're using. You can test this out by grabbing the side of your browser window and dragging it back and forth. Notice how the background image on your landing page changes size and dimensions as you make your window smaller and larger. You'll need to design your background image so that it looks great on a wide variety of screen sizes that are both horizontally and vertically oriented.
Background images are hidden on mobile devices to save space and keep your donors focused on your donation form. Remember to not rely on the background photo to convey critical information because donors who are using mobile devices won’t be able to see it.