This document summarizes a talk on improving website performance. It discusses that the average load time of a web page is 4.9 seconds according to Google, and load times over 500 ms can result in a 20% drop in traffic. It emphasizes that 80-90% of end user response time is spent processing items on the front end like JavaScript and CSS. It provides tips for speeding up pages such as making fewer HTTP requests, using a content delivery network, adding expiration headers, gzipping components, placing stylesheets in the head and scripts at the bottom, avoiding CSS expressions, making JS and CSS external, reducing DNS lookups, minifying JavaScript, and more. It also lists tools that can help with analysis and optimization like
5. The Need for Speed
"Average load time of a web page is 4.9 seconds"
- Urs Hölzle, Google
6. The Google Analytics exit rate for different page load times collected from Wikia data. Measured over 29 million pageviews
7. The Need for Speed
"Average load time of a web page is 4.9 seconds"
- Urs Hölzle, Google
8. The Need for Speed
"Average load time of a web page is 4.9 seconds"
- Urs Hölzle, Google
"The goal should be around 100 ms,
the time it takes for a reader to turn the page in a book"
- http://oreil.ly/bvYNk3
9. The Need for Speed
Google: +500 ms -20% traffic*
Amazon: +100 ms -1% sales*
* http://bit.ly/9iRqAu
12. the importance of frontend
performance
9% 91%
17 83%
%
iGoogle, primed cache
iGoogle, empty cache
Steve Souders http://bit.ly/Zxh4m
13. time spent on the frontend
Empty Cache Primed Cache
www.aol.com 97% 97%
www.ebay.com 95% 81%
www.facebook.com 95% 81%
www.google.com/search 47% 0%
search.live.com/results 67% 0%
www.msn.com 98% 94%
www.myspace.com 98% 98%
en.wikipedia.org/wiki 94% 91%
www.yahoo.com 97% 96%
www.youtube.com 98% 97%
Steve Souders http://bit.ly/Zxh4m April 2008
14. The Performance Golden Rule
80-90% of the end-user response time is
spent on the frontend. Start there.
greater potential for improvement
simpler
proven to work
Steve Souders http://bit.ly/Zxh4m
31. 1. MAKE FEWER HTTP REQUESTS
2. USE A CDN
3. ADD AN EXPIRES HEADER
4. GZIP COMPONENTS
5. PUT STYLESHEETS AT THE TOP
6. PUT SCRIPTS AT THE BOTTOM
7. AVOID CSS EXPRESSIONS
14 RULES
8. MAKE JS AND CSS EXTERNAL
9. REDUCE DNS LOOKUPS
10. MINIFY JS
11. AVOID REDIRECTS
12. REMOVE DUPLICATE SCRIPTS
13. CONFIGURE ETAGS
14. MAKE AJAX CACHEABLE
52. Want to learn more?
Videos from Velocity 2010 http://bit.ly/bL0Msz
Read Steve Souder's books,
"High Performance Web Sites" & "Even Faster Web Sites"