This is the step that allows you to provide a different italy business email list version of the image based on the device or its orientation. In short, it is the heart of responsive optimization. Its concrete application involves different source elements to indicate different image files.
As you can see from the example, we have another attribute used to optimize this step. Namely the srcset , an element that is inserted to simplify the job of choosing the file based on the type of request made by the device. In short, srcset tells the browser which is the best image.
But what about background images? What is the ideal solution to insert a responsive visual? Use the CSS @media (min-width) to make sure that the file is downloaded and applied only if the browser has a width greater than the chosen one. Here is an example.
Replacing the image via Javascript can be a solution since you can check the device and perform the operation by determining the number of pixels of the device with the height and width of the screen. It must be said that it is not the best in terms of general optimization since it causes an increase in the weight of the page and slows down the image upload.