Chapter 1: Web Performance Matters
The Cost of Poor Performance
Web obesity, slow downloads, and poor performance hit everyone—site users, online business owners, and even those who’ve never accessed the Web.
User Costs
At the start of 2020, the average web page comprises:
- 27KB of HTML content
- 64KB of CSS split over seven style sheets
- four fonts, totaling 122KB
- 410KB of JavaScript in 20 source files
- 31 images, requiring 980KB of bandwidth (a third of these are off screen and may never be viewed!)
The total: 1,940KB of data made over 74 HTTP requests, which takes seven seconds to fully appear on the average user’s desktop worldwide. This increases ...
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