javascript slow in IE but fast in Firefox

Question

It is very slow to access this page using IE, but much faster using Firefox. Especially when I increase the number of nodes of people. Any ideas what is wrong?

http://thejit.org/static/v20/Jit/Examples/RGraph/example1.html

BTW: IE is even slow when accessing from local file system.

thanks in advance, George

Answer 1

Internet Explorer's Javascript engine is slower than that from other web browsers, at least when using IE with versions lower than 9. So, if you're using IE 6, 7 or 8, now you know why.

Like raynjamin said, try testing IE using Sunspider.

The latest stable Firefox (3.6) is fast, but for example, Google Chrome is even faster. A browser's Javascript speed depends on its underlying implementation.

Update: to give you an idea of how "fast" IE is compared to other browsers, I've done a benchmark on my own computer using Sunspider 0.9.1. Here are the results:

- Internet Explorer 8: 5039.8ms
- Firefox 3.6:          967.9ms (loaded with extensions)
- Chrome 9:             276.3ms
- Opera 10.6:           293.2ms
- Safari 5:             397.0ms

As you can see, IE 8 is about 5 times slower than Firefox 3.6 and almost 20 times slower than Chrome 9, at least when using Sunspider tests. That is a drastic difference and you can see that IE 8 isn't all that fast.

Update 2: There is one way to make IE faster. A plugin called Chrome frame exists. Using this plugin will make IE faster since it will use Chrome's engine. I haven't tried it personally, but I've heard good things about it.