Chapter 18: Compressing the Web

Table 18.2: Content Encoding Average Compression Ratios for Different Web Site Categories (file size in bytes)
Web Site Type		HTML, CSS, and JS Files Only			All Files Including Graphics
(Average for 5 Web Sites)	Number of Files	Original Size	Compressed Size	Savings	Original Size	Compressed Size	Savings
High-Tech Company	14	26,531	5,092	79%	60,650	39,211	35%
Newspaper	37	74,688	16,218	79%	150,220	91,749	40%
Web Directory	11	36,096	13,296	69%	50,168	27,368	46%
Sports	24	41,011	10,167	74%	110,530	79,686	27%
Average	22	44,582	11,193	75%	92,892	59,504	37%

On average, the text portion of these sites was compressed by 75 percent. Overall, compression would save 37 percent in total file size.

Note: This table is from page 412 of Chapter 18: Compressing the Web from Speed Up Your Site: Web Site Optimization.

Table 18.2: Content Encoding Average Compression Ratios for Different Web Site Categories (file size in bytes)