What is Srcset?
Srcset は、表示デバイスの画面サイズに関係なく、応答性の高いモバイル フレンドリーな画像を表示するために、異なる画面サイズに異なる画像を指定する HTML 画像属性です。
The srcset attribute contains the URL of multiple images and the screen size at which each image should be displayed. So, in essence, visitors with devices with wide screens are shown larger images, while those with smaller screens are shown smaller images.
The srcset attribute is specified using the format srcset="url size, url size" where the URL points to the location of the image and size specifies the screen size at which the image should be displayed.
The attribute can be included inside the image HTML element, as shown below.
<img srcset="yoga-mat-480w.png 480w, yoga-mat-800w.png 800w" />