Dries Buytaert

Faster is better

Through a presentation from Nicole Sullivan, a former member of Yahoo's Exceptional Performance Team and co-author of O'Reilly's upcoming book on performance optimization, I came across the following data points:

  • Amazon: 100 ms of extra load time caused a 1% drop in sales. (Source: Greg Linden, Amazon)
  • Google: 500 ms of extra load time caused 20% fewer searches. (Source: Marrissa Mayer, Google)
  • Google: trimming page size by 30% resulted in 30% more map requests. (Source: Marrissa Mayer, Google)
  • Yahoo!: 400 ms of extra load time caused a 5 to 9% increase in the number of people that clicked "back" before the page even loaded. (Source: Nicole Sullivan, Yahoo!)

While we all knew this was true (and while I'd like more detail on these tests), it is nice to have some quantitative data from different sources. Long story short: even the smallest delay kills user satisfaction. Let's make Drupal even snappier! (Hat tip: Peter Van Dijck)

— Dries Buytaert

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