You can upload your perfectly designed channel art in a matter of seconds to your YouTube channel. The following image will give you an idea of what we have been discussing so far. That goes this way, 1546×423 pixels is the safest zone, larger pics and text could get cropped on different devices.
The file that you are uploading should have the minimum dimensions of 2048×1152 pixels.There are a lot of factors you need to take into consideration while detailing your channel art. However, if you think that once you have uploaded an image or a poster of the prescribed size your task is done, you are wrong my dear friend. YouTube requires you of uploading a channel art that is 2560×1440 pixels.