Web front-end page performance optimization

Some commonly used optimizations:

1. Encourage front-end development engineers to achieve structural semantics when writing xhtml (the benefits of tag semantics: 1. Conducive to search engines; 2. Clear structure facilitates teamwork; 3. Have It is helpful for blind screen readers. As for how to make labels semantic, it depends on personal understanding. I also feel that this aspect is vague, and it probably has something to do with personal habits.)

2. Optimize the number and size of css and js files (generally, it is recommended that css and js be externally connected to reduce repetitive code and code reuse).

3. Optimize the number and size of background images (use images in PNG8 format combined with css sprite. A large number of background images will affect the server and increase the number of http requests.).

4. Put the style sheet at the top; put the script at the bottom of the page; use instead of @import.