What is spoofgui?

SpoofGUI is a Windows desktop application that provides a graphical interface for SNI spoofing, a network technique used to bypass certain types of connection filtering. It is a fork of an existing command-line tool called SNI-Spoofing, and its purpose is to make that tool accessible through a proper Windows UI without requiring manual command-line setup. The application is not a VPN. It works by running a local listener that intercepts outbound connections and substitutes a different server name in the initial TLS handshake, which is the part of a secure connection where the client announces which website it wants to reach. It bundles two other network tools: Xray, which handles proxy connections for protocols like VLESS, VMess, Trojan, and Shadowsocks, and sing-box, which can route all operating system traffic through a network tunnel. The three modes available are a standard proxy mode that only routes traffic from apps you configure manually, a tunnel mode that routes everything, and a system proxy mode that sets Windows-level proxy settings. The interface includes several sections. One manages SNI spoofing profiles, where you define which IP and port to connect to and what fake server name to send. Another handles proxy server configurations, where you can paste connection strings in standard formats and switch between them. A scanner section can bulk-test domain names and flag which ones are hosted on Cloudflare, since those domains are commonly used as the fake server name in SNI spoofing setups. The app is self-contained: the release installer downloads the required third-party binaries automatically and does not require Python.NET, or the proxy tools to be pre-installed. It requires administrator privileges because packet manipulation at the network level needs elevated access. Builds are available for 64-bit and 32-bit Windows. ARM64 is not supported because one of the underlying drivers has no ARM64 version. The project is licensed under GPL-3.0, inherited from the upstream tool it is based on.