The maximum resolution and the exact dimensions we use for the main images on your trip page and itinerary builder is 1440x500 on a standard Macbook computer in full-width window view. 

However, it's advisable to upload images of around 1440x720 size, as the part of the image that is displayed depends on the browser width. 

Please note that in standard viewing mode, the top and the bottom of the picture will not be shown (only 1440x500 will be shown for most window sizes).