What is fastest children() or find() in jQuery?

children() only looks at the immediate children of the node, while find() traverses the entire DOM below the node, so children() should be faster given equivalent implementations. However, find() uses native browser methods, while children() uses JavaScript interpreted in the browser. In my experiments there isn't much performance difference in typical cases.

Which to use depends on whether you only want to consider the immediate descendants or all nodes below this one in the DOM, i.e., choose the appropriate method based on the results you desire, not the speed of the method. If performance is truly an issue, then experiment to find the best solution and use that (or see some of the benchmarks in the other answers here).

This jsPerf test suggests that find() is faster. I created a more thorough test, and it still looks as though find() outperforms children().

Update: As per tvanfosson's comment, I created another test case with 16 levels of nesting. find() is only slower when finding all possible divs, but find() still outperforms children() when selecting the first level of divs.

children() begins to outperform find() when there are over 100 levels of nesting and around 4000+ divs for find() to traverse. It's a rudimentary test case, but I still think that find() is faster than children() in most cases.

I stepped through the jQuery code in Chrome Developer Tools and noticed that children() internally makes calls to sibling(), filter(), and goes through a few more regexes than find() does.

find() and children() fulfill different needs, but in the cases where find() and children() would output the same result, I would recommend using find().