Szathmáry László honlapja @ DEIK

$ nim c prg.nim

𝥶Compiles the program in debug mode. Faster compilation, slower EXE.

$ nim c -d:release prg.nim

𝥶Compiles the program in release mode. Slower compilation, fast EXE. The EXE is smaller.

Create a small EXE

I took the same program and compiled it with different options. File sizes are indicated.

$ nim c prg.nim                                              # 98336 bytes

$ nim c -d:release prg.nim                                   # 69288 bytes

$ nim c -d:release --opt:size prg.nim                        # 38168 bytes

$ nim c -d:release --opt:size --passL:-s prg.nim             # 27120 bytes

$ nim c -d:release --opt:size -d:quick --passL:-s prg.nim    # 26912 bytes

"--passL:-s" calls "strip -s"

Applying UPX

If you want to further minimize the size of the binary, you can also experiment with upx. Take the smallest binary and try these:

$ upx <binary>           # fast; good compression

$ upx --best <binary>    # better compression

$ upx --lzma <binary>    # even better than "--best" :)

After UPX, always try the EXE to check if it still works.

Compilation

Create a small EXE

Applying UPX