In what size should I draw a mobile site design?

Question

Design

In what size should I draw a mobile site design in Photoshop?

Answer 1

375x728 (This is the size from the Google PageSpeed ​​Insights test for mobile devices)

Answer 2

320 of course

Answer 3

css-pixels:
mydevice.io/devices
"smartphones_vert" - (min-width: 320px) and (max-width: 599px)
"smartphones_vert" - (min-width: 480px) and (max-width: 799px)
"tablets_vert" - (min-width: 600px) and (max-width: 1024px)
"tablets_horiz" - (min-width: 800px) and (max-width: 1440px)
"monitors_vert" - (min-width: 1025px)
"monitors_horiz" - (min-width: 1441px)