I have a gorilla/mux based web service written in Golang. I've observed that the exact same code produces a binary of size more than 10 MB on my Windows 10 Pro Machine while its about 7 MB on my colleague's Windows 10 Pro Machine. On yet another colleague's MacBook Pro running OS X Yosemite, the binary is just a bit over 11 MB in size. What does this binary actually contain?!
It may be due to different architectures (GOARCH env variable). Run go env to verify. Compiled binary to 386 and to amd64 differs significantly (compiled to amd64 is significantly bigger), but it should be close if the architecture is the same with different OS.
Also the Go version itself matters a lot, Go 1.7 reduced the compiled binary size. See blog post Smaller Go 1.7 binaries for details.
Also I assume it's the same, but whether debug info is excluded can reduce the compiled binary size significantly.