FishNet vs netcode.io

FishNet is a networking solution for Unity games using a client-server model and a server-authoritative design. It supports dedicated servers, while developers can also run a server and client together for development and testing. Users may choose a host, including self-hosting or player-hosted servers, and the free plan has no CCU caps or paywalls. Its high-level API synchronizes state, logic, and objects; events and inheritance provide lower-level functionality. Built-in client-side prediction includes desynchronization smoothing and Rigidbody prediction, and Addressables support covers network scenes and prefabs. Other listed tools include buffered remote calls, area-of-interest controls, configurable SyncTypes, tick-based timing, and broadcasts. Customizable authenticators can require client authentication before server communication. Communication is unencrypted by default; FishyUnityTransport can enable DTLS for UDP or TLS for WebSocket. FishNet costs nothing. FishNet Pro costs $50, paid once and adds lag compensation and automatic removal of sensitive server logic from client builds. The documentation says prediction collider components currently support primitive shapes such as boxes, spheres, and circles.

netcode.io is a free, open-source client/server protocol for real-time multiplayer games. It uses UDP to exchange unreliable, unordered packets without TCP head-of-line blocking. Game backends can issue connect tokens that authorize clients, while servers assign connecting clients to configured slots and reject connections when slots are full. The protocol supports clean disconnects and timeouts for hard disconnects. Packets are encrypted and signed with libsodium, with protections described against crafted packets, replay attacks, and amplification attacks. IPv4 and IPv6 are supported, along with packet tagging intended to reduce Wi-Fi jitter. Implementations are listed for C, C#, Go, Rust, Unity, Unreal Engine 4, and TypeScript. Builds use CMake on Windows, macOS, and Linux, with CMake 3.16 or later and a vendored libsodium subset by default. The BSD 3-Clause project documents REST-based token requests and reports a nonce-reuse issue affecting versions 1.3.5 and earlier, fixed in 1.4.0.