Even when targeting just the iPhone, redirecting to mobile-friendly sites is already causing problems for the web. This will only get worse as sites begin to detect user agents for other mobile browsers. We are headed towards a fragmented internet, where desktop sites and mobile sites live in independent ecosystems and movement between them is fragile and perilous.
What is a good solution for this problem? Don’t say user agents. Peeking at user agents is so last decade. Media queries are part of the answer, but mobile phones have limited screen space and performance is crucial. There’s a lot of content that is best to not even load. How do web developers detect these performance-sensitive environments and react accordingly?
Don’t. Treat *everything* as a “performance-sensitive environment”. If you have content that you feel comfortable presenting your site without, throw it away; it must not really have content in it, just presentation.
Certainly I’d suggest trying to scale well down to small screens, within reason. But in terms of not loading content, why not make your site faster for standard computer users too?
I agree. Don’t send to anyone something you wouldn’t send to mobile users.
One of the big problems with the mobile web dichotomy is that website operators continue to expect desktop users’ screens to be of a certain width. Imagine what a boon to productivity it would be if users en masse would become comfortable running applications taking up less than half a screen, and developers would send the appropriate content and style sheets down the pipe that allows everyone to do so. For example, the display I’m using now is 1280 pixels across and physically wider than two typical pages from a book, even laid flat. Yet with most websites, I can’t view more than one page on the same screen without invoking cumbersome horizontal scroll. Instead I’m required to read paragraphs at widths shown to cause reading efficiency to drop.
It might be a good idea reading W3C recommendations about mobile web development: http://www.w3.org/mobile