Much recent discussion has focused on the nature of artifacts, particularly on whether artifacts have essences. While the general consensus is that artifacts are at least intention-dependent, an equally common view is function essentialism about artifacts, the view that artifacts are essentially functional objects and that membership in an artifact kind is determined by a particular, shared function. This paper argues that function essentialism about artifacts is false. First, the two component conditions of function essentialism are given a clear and precise formulation, after which counterexamples are offered to each. Second, ways to handle the counterexamples suggested by Randall Dipert and Simon Evnine are considered and rejected. Third, I then consider the prospects for restricting function essentialism to so-called technical artifacts, as Lynne Baker does, and argue that this, too, fails. This paper thereby consolidates the scattered literature on function essentialism and shows that, despite the seeming plausibility of the thesis, it should be rejected as an account of artifact essences.