Photos should be large enough for proper viewing on most screens. A good rule of thumb is at least 1080x1080 - which is sufficient for full HD screens.
Photos can be large - we haven't run into an issue where photos resolution is too high. They will be optimized and saved for screens, so uploading them will not retain the image quality if you are looking to use the site as a cloud storage to print later. However, the upload time may be slower based on your internet speed if the photo is abnormally large in size.
The photos should be in a .jpeg or .png format - GoRevival does not support Raw files of any type.
Photos will be displayed in an sRGB color space.