Yahoo’s Stoyan Stefanov recently had a series on image optimization. His breakdown on page weight was particularly fascinating. Google’s home page is 75% image, weight-wise, because there’s very little to it besides the logo and search box.
Stefanov also posted a good run-down on file types, which is less snarky than the opinionated-but-useful Reddit thread. But for quick fun, see the image type comic that the Reddit folks are discussing.
While I love PNG for its clarity, I often end up choosing JPG for screenshots on Webmonkey because of size. PNG is often 10x the JPG version, with little loss in quality.
But aren’t we all on broadband now? According to a recent study, no. Just over half of Americans have home broadband connections. However, another study shows that 90% of active users have fast connections.
That said, Mobile use is expected to increase, and its speeds are not nearly up with broadband. Plus, if you’re serving bigger images from your own server, you have to pay for that bandwidth, which can add up with significant traffic. All this means image optimization is still relevant, even when many do have access to fast connections.