๐. ๐๐ข๐ง๐ข๐ฆ๐ข๐ณ๐ ๐๐๐๐ ๐๐๐ช๐ฎ๐๐ฌ๐ญ๐ฌ
Websites are mainly slow because of too many (or too large) HTTP requests. We can eliminate unnecessary request by :
(A) ๐๐ผ๐บ๐ฏ๐ถ๐ป๐ฒ๐ฑ ๐ณ๐ถ๐น๐ฒ๐ : js to a file, css to a file
(B) ๐๐ฆ๐ฆ ๐๐ฝ๐ฟ๐ถ๐๐ฒ๐ : CSS Sprites are the preferred method for reducing the number of image requests.
(C) ๐๐ผ๐บ๐ฏ๐ถ๐ป๐ฒ ๐๐ผ๐๐ฟ ๐ฏ๐ฎ๐ฐ๐ธ๐ด๐ฟ๐ผ๐๐ป๐ฑ ๐ถ๐บ๐ฎ๐ด๐ฒ๐ ๐ถ๐ป๐๐ผ ๐ฎ ๐๐ถ๐ป๐ด๐น๐ฒ ๐ถ๐บ๐ฎ๐ด๐ฒ and use the CSS background-image and background-position properties to display the desired image segment.
๐. ๐๐ฌ๐ ๐ ๐๐จ๐ง๐ญ๐๐ง๐ญ ๐๐๐ฅ๐ข๐ฏ๐๐ซ๐ฒ ๐๐๐ญ๐ฐ๐จ๐ซ๐ค ๐๐๐
- A CDN is essentially many optimized servers around the world that deliver web content to users
based on their geographic location. - This means big performance improvements for site users. Because, say, ๐ถ๐ณ ๐ฎ ๐ฝ๐ฒ๐ฟ๐๐ผ๐ป ๐ฎ๐ฐ๐ฐ๐ฒ๐๐๐ถ๐ป๐ด ๐๐ผ๐๐ฟ ๐๐ถ๐๐ฒ ๐ถ๐ป ๐๐ป๐ฑ๐ถ๐ฎ, ๐๐ต๐ฒ๐ ๐๐ถ๐น๐น ๐ฏ๐ฒ ๐ฟ๐ฒ๐๐ฟ๐ถ๐ฒ๐๐ถ๐ป๐ด ๐๐ฒ๐ฏ ๐ฐ๐ผ๐ป๐๐ฒ๐ป๐ ๐ณ๐ฟ๐ผ๐บ ๐ฎ ๐๐ฒ๐ฟ๐๐ฒ๐ฟ ๐ป๐ฒ๐ฎ๐ฟ๐ฏ๐โฆ Simple!
๐. ๐๐ฌ๐ ๐๐ฉ๐ญ๐ข๐ฆ๐ข๐ณ๐ ๐๐ฆ๐๐ ๐๐ฌ
- Image sizes make a huge difference to site speed. – – The larger content/images, the slower the site.
we could achieve this by using –
(A) ๐๐ต๐ฎ๐ป๐ด๐ถ๐ป๐ด ๐๐ต๐ฒ ๐ฟ๐ฒ๐๐ผ๐น๐๐๐ถ๐ผ๐ป : reducing the โqualityโ of the image (and thereby the file size).
(B) ๐๐ผ๐บ๐ฝ๐ฟ๐ฒ๐๐๐ถ๐ป๐ด ๐๐ต๐ฒ ๐ฝ๐ถ๐ฐ๐๐๐ฟ๐ฒ : increasing the efficiency of image data storage.
(C) ๐๐ฟ๐ผ๐ฝ๐ฝ๐ถ๐ป๐ด ๐๐ต๐ฒ ๐ฝ๐ถ๐ฐ๐๐๐ฟ๐ฒ: when cropping, you are cutting out unneeded areas and thus making the image smaller in size.
๐. ๐๐ฎ๐ญ ๐๐๐ซ๐ข๐ฉ๐ญ๐ฌ ๐๐ญ ๐ญ๐ก๐ ๐๐จ๐ญ๐ญ๐จ๐ฆ
- Javascript files can load after the rest of your page.
- The simplest solution is to place your external Javascript files at the bottom of your page, just before the close of your body tag.
- Now more of your site can load before your scripts.
๐. ๐๐ฌ๐ ๐๐๐๐๐ซ ๐จ๐ซ ๐๐ฌ๐ฒ๐ง๐ ๐๐ญ๐ญ๐ซ๐ข๐๐ฎ๐ญ๐๐ฌ
(when placing external .js files on your site)
(A) Async tags ๐น๐ผ๐ฎ๐ฑ ๐๐ต๐ฒ ๐๐ฐ๐ฟ๐ถ๐ฝ๐๐ ๐๐ต๐ถ๐น๐ฒ ๐๐ต๐ฒ ๐ฟ๐ฒ๐๐ ๐ผ๐ณ ๐๐ต๐ฒ ๐ฝ๐ฎ๐ด๐ฒ ๐น๐ผ๐ฎ๐ฑ๐, but this means scripts can be loaded out of order.
- Basically, lighter files load first.
This might be fine for some scripts, but can be disastrous for others.
(B) The defer attribute ๐น๐ผ๐ฎ๐ฑ๐ ๐๐ผ๐๐ฟ ๐๐ฐ๐ฟ๐ถ๐ฝ๐๐ ๐ฎ๐ณ๐๐ฒ๐ฟ ๐๐ผ๐๐ฟ ๐ฐ๐ผ๐ป๐๐ฒ๐ป๐ ๐ต๐ฎ๐ ๐ณ๐ถ๐ป๐ถ๐๐ต๐ฒ๐ฑ ๐น๐ผ๐ฎ๐ฑ๐ถ๐ป๐ด. It also runs the scripts in order.