Issue link: https://read.uberflip.com/i/1146286
146 | Index stylesheets, 37–44 blank white screen, 39–42 avoiding, 43 examples of stylesheet at bottom versus at top, 39–42 CSS at bottom, 39 CSS at top, 41–42 flash of unstyled content, 43 avoiding, 43 number for top 10 U.S. web sites, 85 problem with putting at bottom of documents, 38 T text as image, 115 Theurer, Tenni, 25 top 10 U.S. web sites CDN service providers, 19 components with Expires header, 26 ETags, 94–95 Expires header and max-age directive, 24 gzip use, 30 how performance tests were done, 105 maximum TTL values sent to clients for, 65 minification, 69 minifying inline scripts, 73 number of scripts and stylesheets, 85 page weight, 103 percentage of time spent downloading, 4 performance summary, 103 redirects, 79 response times, 103 scripts and stylesheets, 15 YSlow grade, 103–105 TRACE request, 6 TTLs DNS caching and, 63–66 maximum TTL values sent to clients for top 10 U.S. web sites, 65 U URLs, prettier, 84 V visual feedback, 37 Vrije Universiteit, 20 W Web 2.0, 96–102 defined, 97 relationship between Web 2.0, DHTML, and Ajax, 96 web page performance, 1 Wikipedia CSS sprites, 130 Expires header, 131 gzip, 131 percentage of time downloading, 4 performance recommendations, 130–131 PNG images, 131 (see also top 10 U.S. web sites) X XMLHttpRequest, 83 XMLHttpRequest Beacon (example), 83 Y Yahoo!, 1, 4 CSS sprites, 132 domains, 133 HTTP requests, 133 percentage of time downloading, 4 performance recommendations, 132–133 scripts, 133 two URLs referencing same image, 133 (see also top 10 U.S. web sites) Yahoo! Mail Ajax caching example, 99–101 Yahoo! Search, 4 Yahoo! Shopping and Akamai's CDN, 21 Yahoo! UI (YUI) Connection Manager for Ajax, 98 YouTube Etags, 137 Expires header, 137 parallelization, 137 percentage of time downloading, 4 performance recommendations, 135–137 (see also top 10 U.S. web sites) YSlow, 106 grades defined, 104 top 10 U.S. web sites, 103–105