This post originated from an RSS feed registered with Ruby Buzz by Amos King. Original Post: Change Classes not Styles Feed Title: DirtyInformation Feed URL: http://feeds.feedburner.com/Dirtyinformation Feed Description: Information about Ruby/Rails/JRuby/WebDevelpoment/whatever. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by Amos King Latest Posts From DirtyInformation

I've been working with some javascript lately and wanted to see if it made a difference if I was changing the class or inline style of an element. I had heard that changing classes was faster, but can it really make a big difference?

YES!!!

I coded up a quick example. Here are the results in ms(all on osx):

• Safari 5.0.2
  • changing style:123
  • changing class:15 - 87.8% faster
• Chrome 7.0.517.44
  • changing style:115
  • changing class:16 - 86.1% faster
• Firefox 3.0.15
  • changing style:333
  • changing class:99 - 70.3% faster
• Opera 10.10
  • changing style:554
  • changing class:111 - 80% faster

I really didn't expect those kinds of results. Kind of amazing!