FxCop is a free static code analysis tool from Microsoft that checks .NET managed code assemblies for conformance to Microsoft's .NET Framework Design Guidelines.

Unlike StyleCop, or the Lint programming tool, for the C programming language, FxCop analyzes the compiled object code, not the original source code. It uses CIL parsing and callgraph analysis to inspect assemblies for more than 200 different possible coding standards violations in the following areas:

FxCop includes both GUI and command line versions of the tool. Microsoft Visual Studio 2005 and Visual Studio 2008 Team System Development Editions both include a "Code Analysis" feature based on FxCop. For Visual Studio 2010 the corresponding, and slightly enhanced, static code analysis features are included in the Premium and Ultimate editions. FxCop 10.0 is included in the Microsoft Windows SDK for Windows 7.

FxCop provides a tool to help developers to follow their company's coding standards. FxCop does code analysis to check whether the new code is compliant with the coding standards and naming conventions followed by the company. FxCop will ensure that the specified rules are used in the source code.^{[citation needed]}