Xray and Sing-box — Modern Proxy Cores
Overview
Xray-core and Sing-box are versatile proxy platforms that support numerous protocols and provide flexible traffic routing. They have replaced V2Ray-core and become the standard for building proxy infrastructure, especially in the context of bypassing internet censorship.
Xray-core
What It Is
Xray-core is a fork of V2Ray-core, initiated in 2020 following disagreements within the V2Ray community. Xray introduced key innovations: XTLS, Reality, and improved performance.
Key Features
Protocols:
- VLESS (with XTLS and Reality)
- VMess
- Trojan
- Shadowsocks
- SOCKS5
- HTTP
Transports:
- TCP, WebSocket, gRPC, HTTP/2, QUIC, mKCP
- SplitHTTP (new transport for CDN)
Routing:
- By domain, IP, GeoIP, GeoSite
- By protocol, port, user
- Balancer (distribution among servers)
Unique Features:
- XTLS-Vision — optimized TLS proxying
- Reality — masquerading as a real website
- Fallback — show a legitimate website upon suspicious connection
Xray Architecture
Xray operates on the principle of inbound → routing → outbound:
Inbounds — listen for incoming connections (ports, protocols).
Routing — routing rules based on traffic attributes.
Outbounds — determine where to send traffic (proxy server, direct connection, blocking).
Performance
Xray with XTLS-Vision is significantly faster than V2Ray:
- 30-50% higher throughput
- 40-60% lower CPU load
- Efficient TLS processing (zero-copy with XTLS)
Sing-box
What It Is
Sing-box is a versatile proxy platform written in Go. It was designed from scratch to be modular and extensible. Author: SagerNet (sekai).
Key Features
Protocols:
- VLESS, VMess, Trojan, Shadowsocks
- Hysteria / Hysteria2 (UDP-based, optimized for high packet loss)
- TUIC (based on QUIC)
- Naive (Chrome-based proxy)
- WireGuard
Routing:
- Rule sets (downloadable rule collections)
- GeoIP/GeoSite with lazy loading
- DNS routing and DNS hijacking
- Support for Clash-like format
Platforms:
- Linux, Windows, macOS
- Android (SFA — Sing-box for Android)
- iOS (SFI — Sing-box for iOS)
- Apple TV, tvOS
Differences from Xray
| Parameter | Xray-core | Sing-box |
|---|---|---|
| Basis | V2Ray Fork | From scratch |
| Language | Go | Go |
| Config | JSON | JSON |
| XTLS/Reality | Yes (original) | Yes (ported) |
| Hysteria | No | Yes |
| TUIC | No | Yes |
| WireGuard | No | Built-in |
| Mobile Clients | Via V2rayNG | Native (SFA/SFI) |
| Modularity | Medium | High |
| Documentation | Medium | Good |
Comparison of Approaches
Xray — Focus on VLESS/Reality
Xray is focused on the development of VLESS + XTLS + Reality. It is the best choice if the primary goal is to bypass DPI with maximum performance.
Sing-box — Versatility
Sing-box supports more protocols (Hysteria, TUIC, WireGuard) and offers more flexible routing. It is the best choice for multi-protocol configurations.
Practical Scenarios
Personal Proxy Server
Installing Xray or Sing-box on a VPS to bypass censorship. VLESS+Reality is the most robust configuration.
Proxy for a Team
Multi-user configuration with different UUIDs for each user. Xray supports fallback between users.
Proxy Router
Sing-box on a router (OpenWrt) for transparent proxying of all home network traffic.
Multi-protocol Gateway
A single server accepts connections via VLESS, VMess, Trojan, Shadowsocks on different ports. Each user chooses their preferred protocol.
Proxy Chain
Sing-box allows configuring a chain: your traffic passes through several servers sequentially (proxy chain via configuration).
Ecosystem
Control Panels
- 3x-ui — web panel for Xray (user management, traffic monitoring)
- Marzban — advanced panel with Xray support
- Hiddify Manager — panel with Xray and Sing-box support
Subscription
Subscription format for automatic client configuration updates. Supported by V2rayNG, Clash, Sing-box.
Rule Providers
- GeoIP / GeoSite databases from V2ray/Xray
- Rule sets from the Sing-box community
- Clash-compatible rules
Choosing Between Xray and Sing-box
Choose Xray if:
- Your primary protocol is VLESS + Reality
- You need maximum XTLS performance
- You use 3x-ui or Marzban
- You are accustomed to the V2Ray ecosystem
Choose Sing-box if:
- You need multiple protocols (Hysteria, TUIC, WireGuard)
- You need a native mobile client
- Flexible routing with rule sets is important
- You are setting up a proxy on a router
Conclusion
Xray and Sing-box are two leading proxy cores, each with its own strengths. Xray dominates the VLESS/Reality ecosystem with superior performance. Sing-box offers versatility and support for a wider range of protocols. For most censorship circumvention tasks, both options work excellently, and the choice depends on specific protocol and platform requirements.