The optimal size for an item photo is a minimum of 570 pixels wide. Etsy retains the aspect ratio of your original, so the height is variable.
If you upload an item photo that is less than 570 pixels wide, Etsy will center your original, smaller image on the listing page.
Horizontal (landscape) orientation images or square images are recommended over vertical (portrait) orientation images for the first photo in the listing. This will ensure the center, focal-point of the image appears in the cropped thumbnail views.
We recommend using an image that is a maximum of 800-1000 pixels wide. Using an original image of this size lets shoppers use the Zoom button to see the larger image. We do not recommend using images that are much larger than 1000 pixels square, as files this large can be difficult to upload.
If you need to resize your images, here are a few online photo editing services that many sellers like to use. These services are easy and free. You can use any one of these tools to resize and edit your images for Etsy.
(Etsy is not affiliated with any of these services.)