> if both were annotated with some kind of hashes of their contents That's exactly what I don't want to do, since it's extra complexity and extra work on my pa

> if both were annotated with some kind of hashes of their contents That's exactly what I don't want to do, since it's extra complexity and extra work on my part. (: > Also, have you compared the performance of whatever you're doing with a simple PJAX-like approach? Considering that browsers are very good at parsing HTML, I wonder how fast that would be compared to doing quite a lot of DOM calls, which you seem to be doing (?). Nope, sorry, I haven't done any benchmarks. From what I've tested the performance is great. If the pages where I use it were heavier then maybe I'd have performance problems, but so far I don't.