I’ve been using this bookmarklet for a little while now. It disables all CSS3 effects on the page you’re viewing, so you can see how it will perform in less capable browsers. It’s becoming less useful as time goes on and older browsers die out but I still use it regularly. For example, I used it in my latest tutorial, Create a 3D Book Animation with CSS, to simulate what happens if a browser doesn’t support CSS transforms.
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