I’m doing a lot of work with SVG at the moment, and something that would be very useful to understand is exactly which parts of a diagram are taking the longest to process and render.

For very complex documents with many thousands (possibly many millions) of elements, knowing that rendering a particular portion of the image is taking n% of the time can help identify which areas of the image need to be re-written to make the image as a whole work better and faster.

SVG optimization is going to become a significant area of development over the coming years, especially for SVG that uses ECMAScript to modify the DOM, because it will help turn todays stuttering experiments into tomorrows smooth graphical web based applications.

So if such a tool doesn’t exist already, someone needs to make it – perhaps as a Firefox plugin. If it does exist… what’s the URL?