When you're creating a Web page, size matters. There's limited space to work with, and page elements take up certain amounts of space. It's a land of constraints, and you've got to know the rules before you get started.
Unfortunately, the browser makers have been naughty, so the rules aren't simple. Each Web browser has its own playing field with its own quirks. If we don't get to know every one of these playing fields, then our pages might very well look crappy in some browser.
Source: Webmonkey
Webmonkey has always had great stuff. I came across this article, that takes a look at the differences in all the major browsers (sans Safari for some reason) with regard to canvas size, text size, and form elements.
They even provide Photoshop files showing the differences in canvas size. Very handy. (Although I had to unzip them in Windows, 10.3 did not like the zip files for some reason.)
