CSS sprites combine multiple images into one image, limiting the number of HTTP requests a browser has to make, thus improving load times. Even under the new HTTP/2 protocol, this remains true.
Under HTTP/1.1, at most one request is allowed per TCP connection. With HTTP/1.1, modern browsers open multiple parallel connections (between 2 to 8) but it is limited. With HTTP/2, all requests between the browser and the server are multiplexed on a single TCP connection. This means the cost of opening and closing multiple connections is mitigated, resulting in a better usage of the TCP connection and limits the impact of latency between the client and server. It could then become possible to load tens of images in parallel on the same TCP connection.
However, according to benchmark results, although HTTP/2 offers 50% improvement over HTTP/1.1, in most cases the sprite set is still faster to load than individual images.
To utilize a spritesheet in CSS, one would use certain properties, such as
background-size to ultimately alter the
background of an element.
background-sizecan be used to utilize a spritesheet.