In general, the recommended size for a background image is 1440 × 1100 pixels.
The background is aligned to the top left of the browser and scales proportionally to fit the width of the browser. If you have important elements you want to always display in the background it's important to keep all of your important elements as close to the top left corner as possible since many devices will have different screen sizes and it is best to cover the majority of browsers.
It is based on your preference where you want the important elements to display exactly, but our recommendation is to keep it as close to the top left corner as possible so it looks best across most desktops and mobile devices.
Please let us know if you have additional questions.
You can always file a support ticket if you have additional questions by clicking the Support button in your dashboard shown here or clicking here to file a support ticket.
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