move these things into initWiv() and cache them: var speed = parseFloat(wivCurve.parentNode.dataset.wivSpeed) var height = parseFloat(wivCurve.parentNo

move these things into initWiv() and cache them: var speed = parseFloat(wivCurve.parentNode.dataset.wivSpeed) var height = parseFloat(wivCurve.parentNode.dataset.wivHeight) var tightness = parseFloat(wivCurve.parentNode.dataset.wivTightness) var thickness = parseFloat(wivCurve.parentNode.dataset.wivThickness) var ctx = wivCurve.getContext("2d"); do this once on init, the canvas context remembers it anyway: ctx.strokeStyle = wivCurve.parentNode.dataset.wivColor != undefined ? wivCurve.parentNode.dataset.wivColor : "#FF0000" don't convert numbers and strings all the time, use numbers and init them to 0 //current frame is tracked on per wiv basis. This is to help with speed calculations if (parseFloat(wivCurve.dataset.count) > 100000) { wivCurve.dataset.count = "0"; } wivCurve.dataset.count = (wivCurve.dataset.count ? parseFloat(wivCurve.dataset.count) : 0) + speed; parseFloat(wivCurve.dataset.count) also is used a lot in that loop. And don't set unneccessary canvas state, this should happen only once per draw loop iteration: [edit, actually, as I said above, the canvas contexts remember it individually, so do this once in initWiv(), and not in the draw loop at all, yay!] ctx.lineWidth = thickness; That's all just at first glance, but I bet you, this would help with slow laptops and whatnot :) Such "small" things really add up when you do them 60 times per second * number of borders. I don't know if setting the canvas width or height to the value it has anyway to clear it (instead of clearing/drawing a rectangle explicitly) is still a useful thing to do, but you might try that as well.