When uploading images to your campaign banner, you'll see that we list the recommended size as 1920 pixels wide by 730 pixels high (1920x730). An image in this size will look best when people view your fundraiser on a large desktop monitor.
With that being said, your fundraising page is responsive. This means that it automatically adapts to the size of screen the person is viewing it on. For screens smaller than 1920x730, images will be cropped as the site "responds" to the size of the screen. This is done in order to retain the overall look of the page (including your buttons, title, countdown timer, and more) on a wide variety of screen sizes.
How to format your images:
As a general rule of thumb, you should format your images in such a way that all "main" content of the image fits within the center 1170 pixels of the entire 1920-pixel-wide image. Anything within this 1170 pixel wide "safe zone" will not get cropped, even on smaller screens.
Here's a diagram illustrating the “safe zone:”
The green box represents the 1170 pixels at the center of the image. Everything that falls within this green "safe zone," will be visible to everyone who visits your page – no matter which type of device they're using. For this reason, any critical aspects of your image should fall within this section.
The red box in the image above shows the full, 1920-pixel-wide image which we recommend you upload. Users with a large enough screen will see everything inside the red box.