Every web developer knows that browsers have a max number of concurrent connections that can be opened to a host at a time. Modern browsers have anywhere from 6-8 per host. You can test this on my simple concurrent connections test page. Open the link and wait ~3 seconds and count the number of boxes you see with content. If you’re in Chrome or Firefox 3+ you’ll see 6 boxes fill up at a time.

Mobile browsers are exactly the same except iOS 4 and Android 2.2 (Froyo) allow 4 concurrent connections. Surprisingly, iPhone OS 3.x allows for 6 (this includes the iPad with 3.2). I’m not exactly sure why Apple decided to drop the max concurrent connections but 2 less connections per device would lessen the load on operator networks (*cough* AT&T).

I don’t have any older Android or iPhone 2.x devices lying around. If anybody has any, feel free to use my concurrent connections test page and post the results in the comments. I’ll update once I get my hands on some more devices next week.