A go-no gauge (or go/no-go) refers to an inspection tool used to check a work piece against its allowed tolerances. Its name is derived from two tests: the check involves the work piece having to pass one test (go) and fail the other (no-go).

A go/no-go gauge is an integral part of the quality process that is used in the manufacturing industry to ensure interchangeability of parts between processes or even between different manufacturers. It does not return a size or actual measurement in the conventional sense, but instead returns a state, which is either acceptable (the part is within tolerance and may be used) or unacceptable.