According to many of the tests on jsperf.com , jQuery is slow. Really slow. The jQuery team gets bug reports from web citizens who've discovered these egregious flaws via jsperf and want them fixed. Now, jsperf.com can be a great tool when used knowledgeably, but its results can also be misinterpreted and abused. For example: Why doesn't jQuery use DOM classList for methods like .addClass()? There are at least three good reasons. It doesn't make any practical performance difference given its frequency of use. It complicates code paths, since classList isn't supported everywhere. It makes jQuery bigger, which makes it load slower for everyone, every time. But this jsperf shows classList is much faster! How can you say that? Well it's possible that test is running afoul of microbenchmark issues , and not measuring what it is supposed to measure due to the increased sophistication of today's JavaScript compilers. This is a big problem with a lot of t
Tomorrow speak what tomorrow thinks in hard words again, though it may contradict everything you said today. -- Emerson