What are css sprites and what are their advantages?

css sprites, also known as css sprites, is a web image application processing method. It is a method of combining multiple images into a single image file for use on the website. Its advantages are: 1. Reduce http requests for web pages and improve page loading speed; 2. Reduce the bytes of images; 3. Reduce naming problems; 4. It is easy to change styles.

The operating environment of this tutorial: Windows 7 system, CSS3&&HTML5 version, Dell G3 computer.

css sprite (Sprite)

CSS Sprites is a performance optimization technique that combines multiple images into a single image file for use on a website Method to improve performance; also known as CSS sprites.

Advantages

a) Reduce http requests for web pages and improve page loading speed

b) Reduce image bytes: merge multiple images The bytes of one picture are less than the sum of bytes of multiple pictures

c) Reduced naming trouble: you only need to name a collection of pictures, instead of naming each small element to improve production efficiency

d) It is convenient to change the style: you only need to modify the color or style of one or a few pictures, and the style of the entire web page can be changed, making maintenance more convenient

Disadvantages

a) When merging pictures, you need to merge multiple pictures into one picture in an orderly and reasonable manner, and leave enough space to prevent unnecessary backgrounds in the section; These are okay, but the most painful thing is the adaptive page under widescreen and high-resolution screens. If your picture is not wide enough, it is easy for the background to break

b) When setting the background, you need to get every The precise position of the background unit

c) It is troublesome to maintain the composite image. If the page background has a slight change, you usually need to change the merged image. It is best to just add the image below instead of changing the existing one. Picture

Why use Sprites?

Web pages often contain multiple images. These include icons, buttons, logos, related pictures and other graphics. When an image is loaded into a page, the browser makes an HTTP request to the server. Loading each image individually requires multiple calls to the HTTP server, which can result in slow download times and high bandwidth usage.

CSS Sprites will combine multiple images into a single image called a sprite sheet or collage. Instead of downloading multiple files, the user downloads a single file and displays the necessary images via offset files (or sprite).

This can reduce calls to the server, reduce the number of downloads required to render web pages, save bandwidth and shorten the download time of the client, and reduce network congestion.

How to use CSS Sprites (sprites)?

Because CSS Sprites are multiple images combined into a single image, multiple images will be placed in a grid-like pattern in the sprite sheet, showing a network distribution.

When a specific image (sprite map) is required, the sprite sheet is generally referenced through the CSS background-images property, and then offset and positioned through the CSS background-position property to obtain the required sprite map, and then Defines the size of the sprite image in pixels.

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