We recommend that the photos for your listing be 1920px wide. That way they’ll look great as ‘Header’ images, or in the Gallery.
Photo file sizes can be a maximum of 1Mb, and you can upload 9 images into your Gallery.
If you need to make your file sizes smaller we recommend:
1. use photo editing software to make them smaller. 1920px wide is big enough.
For example, in Apple Mac Photos select the photo(s) and go to File > Export and select ‘Custom Size’:
2. Or use the free online service, tinypng.com to make the file size smaller.