Why does iOS restrict proxy server usage to Wi-Fi connections only

Security Considerations

1. Protection Against Unsecured Networks: iOS is designed with a strong emphasis on user security. By allowing proxy configurations only on Wi-Fi, Apple aims to minimize potential vulnerabilities that could arise from using proxies on cellular networks, which may be less secure and more susceptible to interception by malicious actors.

2. Data Privacy: When connected to a cellular network, users often expect a certain level of privacy and security. Allowing proxies could expose user data to third-party servers, which may compromise sensitive information.

Performance and Reliability

1. Network Stability: Cellular networks can vary significantly in terms of performance and stability compared to Wi-Fi networks. Proxies can introduce latency and connection issues, which might be more problematic on cellular data. By restricting proxies to Wi-Fi, Apple ensures a more stable and reliable user experience.

2. Configuration Complexity: Managing proxy settings for multiple types of connections (Wi-Fi and cellular) could complicate the user experience. By limiting proxy use to Wi-Fi, iOS simplifies the network configuration process for users.

Technical Limitations

1. Protocol Support: iOS supports HTTP proxies but does not allow SOCKS proxies through its settings. This limitation is likely due to the focus on HTTP traffic, which is more common for web browsing and general internet use, making it more suitable for Wi-Fi configurations where users typically engage in such activities.

2. Lack of Global Settings: Unlike Wi-Fi, cellular data settings are generally managed by the carrier, which may not support custom proxy configurations. This makes it impractical for iOS to implement proxy settings for cellular data without significant changes to how cellular connections are managed.

In summary, the restriction of proxy server usage to Wi-Fi connections on iOS is a deliberate design choice aimed at enhancing security, ensuring performance, and simplifying user experience.