Sing Box

Sing Box is a universal proxy platform licensed under GPLv3. It utilizes system-level Android privileges to enable direct L3 bridge outbound routing for TCP, UDP, and ICMP traffic, bypassing standard network restrictions directly through local network interfaces.

Technical Overview of Sing Box

Sing Box functions as a comprehensive network proxy protocol engine, requiring rooted Android privileges to bypass L3-to-L4 translation for direct traffic forwarding. It maintains strict resource efficiency by unifying HTTP/2 and QUIC parameters, running protocol sniffing directly on the first UDP packet in pre-match routing. Its primary advantage over traditional proxy applications is its native capacity to execute TLS ClientHello spoofing and hardware-level MAC address matching without relying on external dependencies.

Core Features of Sing Box

• L3 Bridge Forwarding: Forwards TCP, UDP, and ICMP traffic directly from TUN endpoints out of a physical network interface.
• Hysteria2 NAT Traversal: Executes UDP hole-punching to establish direct QUIC connections for servers stationed behind NAT.
• Optimistic DNS Caching: Answers queries using expired cached responses instantly while executing background refreshes to minimize tail latency.
• TLS Handshake Spoofing: Broadcasts a forged ClientHello carrying a whitelisted SNI to fool SNI-filtering network middleboxes.

Compatibility & Quick Setup

• Requires a rooted Android environment to successfully execute L3 bridge outbound forwarding and MAC address network resolution.
• Install the APK and grant ADB permissions via Shizuku or system root to activate direct L3 proxy networking.