You may not realise it, but bandwidth is expensive. It costs you time, money, and battery power whenever you download a file larger than it needs to be.
That's why I've become a little bit obsessed with SVG - Scalable Vector Graphics. They're the closest thing to magic that the web has when it comes to image compression. Let me show you what I mean.
This is the standard Twitter Logo. It's 512 * 512 pixels and, even with hefty PNG compression, weighs in at around 20KB.
Here's the same logo rendered as an SVG. Because it is a vector graphic it can be magnified infinitely without any loss of fidelity.
... read the whole story at shkspr.mobi.