Note: Go 1.18 (Q1 2022) does rename interface{} to any (alias for interface{}). See issue 49884, CL 368254 and commit 2580d0e. See the last part of this answer. You can refer to the article "How to use interfaces in Go" (based on "Russ Cox’s description of interfaces"): What is an interface? An interface is two things: it is a set of methods, but it is also a type The interface{} type (or any with