NAT Checker Edge extension security report

NAT Checker is a lightweight extension designed to help users quickly identify their current NAT behavior from inside the browser, without installing command-line tools or running complex local diagnostics. The extension combines WebRTC ICE candidate gathering with WebSocket-based signaling, then presents a clear NAT classification together with detected public IP information in a simple popup interface. After clicking Start, the extension opens a secure signaling connection and creates a WebRTC peer connection using a STUN server. During ICE gathering, it filters and sends UDP server-reflexive candidates, allowing the backend NAT detection service to evaluate mapping and filtering characteristics. Once analysis is complete, the extension displays a normalized NAT type result, such as open internet, full cone, IP restricted, IP and port restricted, symmetric, or blocked. This makes it easy for users to understand whether their network is suitable for peer-to-peer communication, real-time voice/video quality expectations, remote connectivity, and other latency-sensitive scenarios. The user interface is intentionally minimal and practical. It includes Start and Stop controls, real-time status updates, and a rolling log panel that helps users observe each step of the signaling and ICE process. Results are shown in a dedicated section with NAT type, public IP, and error details when applicable. Built-in timeout handling and graceful cancellation improve reliability and prevent hanging sessions. If the user closes or stops the check, the extension cleans up all WebRTC and WebSocket resources to avoid unnecessary background activity. Because it runs in a browser popup, NAT Checker is ideal for quick validation and troubleshooting during development, QA, network support, and end-user self-diagnosis. It is especially useful for teams building WebRTC products, game networking features, remote assistance tools, or any application where NAT behavior can affect connectivity. NAT Checker focuses on clarity, speed, and actionable network insight, giving users an immediate and understandable view of how their current network environment behaves.