Playing around with HTML5 Canvas is a lot of fun, but drawing is really slow and reminds me on GDI+ or Java 2D. The larger the resolution of the drawing canvas is the worse the performance becomes. Doing a little game using the whole browser given size on a Full HD monitor can even slow down on Chromium with a relatively fast CPU (AMD A8-3870). My idea was drawing the canvas in a smaller resolution, the half of the available for example, and scale it up. This is the same way a game console like XBOX 360 and PS3 rendering Full HD or even HD Ready which sometimes is not HD Ready indeed. Scaling elements can be done using CSS3 transform.
Read more if you wants to know about the performance impact by scaling a canvas up instead rendering on a larger one:
read more TEST