The document discusses fourteen techniques for improving web site performance: making fewer HTTP requests, using a content delivery network, simple HTTP headers, Gzip compression, placing stylesheets in the head and scripts at the bottom, avoiding CSS expressions, keeping JavaScript and CSS external, reducing DNS lookups, minifying JavaScript, avoiding redirects, removing duplicate scripts, configuring ETags, making Ajax cacheable. It then analyzes the performance of top websites based on these techniques.

1. High Performance Web Sites
Alexandre Porfírio
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2. #1 Make Fewer HTTP
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3. #2 Use a Content Delivery Network
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4. #3 Simple HTTP header
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5. #4 Gzip compression
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6. #5 Put Stylesheets at the Top
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7. #6 Put Scripts at the Bottom
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8. #7 Avoid CSS expressions
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9. #8 JavaScript and CSS external
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10. #9 Reduce DNS Lookups
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11. #10 Minify JavaScript
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12. #11 Avoid Redirects
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13. #12 Remove duplicate scripts
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14. #13 Configure ETags
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15. #14 Make Ajax cacheable
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16. Uses redirects
 Amazon no
 CNN yes ................. Initial page
 eBay yes ................ Secondary page
 MSN yes ................ Initial page
 Wikipedia yes ................ Secondary page
 Google no
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17. time
Redirect
HTML
Script
Stylesheet
Stylesheet
Stylesheet
Image
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18. External scripts minified
 Amazon ............................................ no
 CNN ............................................ no
 eBay ............................................ yes
 MSN ............................................ yes
 Wikipedia ............................................ no
 Google ........................................... yes
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19. External minified | Inline minified
 Amazon no ........................... no
 CNN no ........................... no
 eBay yes ........................... no
 MSN yes ........................... no
 Wikipedia no ........................... no
 Google yes ........................... yes
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20. Duplicate Script
Scripts Stylesheets
 Amazon 3 .......................... 1
 CNN 11 .......................... 2
 eBay 7 .......................... 2
 MSN 9 .......................... 1
 Wikipedia 3 .......................... 1
 Google 1 .......................... 1
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21. Page weight | Response time
 Amazon 405k ................. 15.9 sec
 CNN 182k ................. 11.5 sec
 eBay 275 k ................ 9.6 sec
 MSN 221k ................ 9.3 sec
 Wikipedia 106k ................ 6.2 sec
 Google 18k ................ 1.7 sec
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22. Gzip | JSMin Dojo | Compressor
 Amazon 48k ............ 7k .................. 6k
 CNN 29k ............. 6k .................. 6k
 Wikipedia 13k ..............5k ................... 5k
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23. Thank you!
Alexandre Porfírio
http://alexandreporfirio.com
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