Determining the CPU architecture of a static library (LIB) on Windows

Solution 1:

Use dumpbin /headers

The machine type is almost the first line you'll get.

It will be 14c for x86 and 8664 for x64

n:>dumpbin lib642.lib /headers

Microsoft (R) COFF/PE Dumper Version
10.00.30319.01 Copyright (C) Microsoft Corporation. All rights reserved.

Dump of file lib642.lib

File Type: LIBRARY

FILE HEADER VALUES 8664 machine (x64

Or

n:>dumpbin Lib32.lib /headers

Microsoft (R) COFF/PE Dumper Version
10.00.30319.01 Copyright (C) Microsoft Corporation. All rights reserved.

Dump of file Lib32.lib

File Type: LIBRARY

FILE HEADER VALUES 14C machine (x86)