320 x 480 (iPhone 3,4) 
375 x 667 (iPhone 6,7,8)
414 x 736 (iPhone 6+,7+,8+ aka Phablet)
375 x 812 (iPhone X,Xs)
414 x 896 (iPhone Xr,XsMax)
480 x 640 (small tablet)
768 x 1024 (iPad - Portrait)
1024 x 768 (iPad - Landscape)
Find out is your website mobile responsive and how will it display on old and new iPhones including the 6 and 6 Plus as well as small tablets and iPads
Note: The content width may not be pixel perfect - 15px is added to the iframes to cater for the scrollbars