Image size requirements are different by module. Below are our recommendations.
Recommended image sizes (width x height in pixels):
Background images: ~2560 x 1440 (should accomodate big screens)
Jumbotron images: 2000 x any height
Product images: 1000 x 1000 (Square aspect ratio)
Full-column size (the largest): 900 x any height
There are some guidelines when it comes to content images you should try to follow. The size of the image you upload depends on the column size where you intend to place it. Ever image that is uploaded is automatically scaled and adjusted to the column width. This means that you only need to upload an image in one size, the system will do the rest for you.
Jumbotron and background images
Images used in Jumbotron modules or as background images require a larger size in order to work well for larger screens. The rule of thumb for background images for a page is that it should cover the entire background in the highest screen resolution. We optimize our background images to 2560 pixels wide, which will typically cover a 27” screen. In most cases, this will be larger than necessary, but if you optimize for this size, you can trust your site to look great on 95% of desktop screens.
Jumbotron images are automatically scaled to a width of 2000 pixels. So if you upload an image larger than that, it will automatically be scaled down to 2000 pixels wide.
Recommended image sizes:
Jumbotron modules: 2000 px width x Any height.
Background images: You should try to optimize it to as big a screen as possible. We optimize to 2560 x 1440. Note the height cannot exceed 2000 pixels.