FishNet

Overview

FishNet is a Unity networking toolkit for multiplayer games, aimed at developers who want control over server hosting and concurrency rather than a provider-defined player cap. Its strongest case is the combination of a server-authoritative design, built-in prediction and a free core; prediction collider support is narrow, and transport encryption takes configuration.

Key features

FishNet’s high-level API synchronizes game state, logic and objects, with events and inheritance available for lower-level behavior. That range gives Unity teams room to build common multiplayer systems while retaining options for more tailored networking code. Its client-server model is server-authoritative by design, supports dedicated servers, and also lets a developer run as both server and client for development and testing.

Built-in client-side prediction, desynchronization smoothing and Rigidbody prediction target responsive movement and reduce visible mismatch between clients. The important limitation is that prediction collider components currently support only primitive shapes such as boxes, spheres and circles. Projects that depend on prediction with other collider shapes should account for that constraint before choosing FishNet.

Other tools include buffered remote calls, reliable and unreliable remote calls, configurable SyncTypes, tick-based timing, broadcasts and area-of-interest controls. Addressables support covers network scenes and prefabs. FishNet Pro adds lag compensation and automatic code stripping, which removes sensitive server logic from client builds.

Authentication is customizable: clients must pass an authenticator before they can communicate with the game server. Transport security is separate from that gate. FishyUnityTransport communication is unencrypted by default, with DTLS available for UDP and TLS for WebSocket when enabled; teams should treat encryption as a deployment configuration, not an automatic property of the transport.

FishNet allows teams to choose any host, including self-hosting or player-hosted sessions, and says it imposes no CCU caps or paywalls. That flexibility avoids a concurrency charge imposed by FishNet, but it also leaves host selection and operation to the project. Community integrations cover voice, hosting and lobby tools, gameplay extensions, utilities and Steamworks wrappers; their authors, rather than FishNet, are responsible for support.

Pricing

The FishNet plan is free at no cost, with no CCU caps or CCU paywalls and the Unity networking solution. It is the natural starting point for individual developers and teams who want to build or operate multiplayer without a FishNet concurrency ceiling.

FishNet Pro costs $50, paid once. It includes Pro features and lifetime access to future updates via the Unity Asset Store. Choose it when lag compensation or automatic stripping of sensitive server logic is important; the free plan does not include those Pro features. Pro purchases can include priority support.

The pricing model is freemium, with paid options from $10. The stated Pro Asset Store listing is $50, paid once, so that is the clear one-time option for the added Pro capabilities.

Platforms

FishNet is for Unity and supports Windows, macOS, Linux, Web, iOS, Android, Xbox, PlayStation and Nintendo through FishyUnityTransport. UDP and WebSocket are the supported transport protocols. Its platform range makes it relevant to teams targeting desktop, mobile, web and consoles, subject to their Unity project and transport choices.

Who it's for

FishNet fits Unity developers who want a server-authoritative foundation, built-in prediction and freedom to choose dedicated, self-hosted or player-hosted servers. It is also a sensible fit for prototypes that need both client and server roles locally. Look elsewhere or plan a workaround if your prediction design relies on non-primitive collider shapes, or if you want encryption enabled without configuring the transport.

Pros and cons

• Pro: No CCU caps or paywalls, while teams can choose their own hosting model; useful when concurrency and host control matter.
• Pro: Prediction, smoothing and Rigidbody prediction are built in, reducing the need to assemble those capabilities from separate tools.
• Pro: The API spans high-level synchronization and lower-level events and inheritance, with Addressables support for network scenes and prefabs.
• Con: Prediction collider components are limited to primitive shapes, which can constrain movement and collision designs.
• Con: Transport communication is unencrypted by default, so teams must enable DTLS or TLS as appropriate.
• Con: Community integrations are not officially maintained or guaranteed by the project, making their support less certain than FishNet’s own documentation and Discord help.

Alternatives

Photon Fusion is worth comparing if a managed concurrency allowance is preferable: its free plan covers one app, games only, approximately 40k MAU and 0.3 TB of monthly traffic, with no CCU burst. FishNet instead makes no CCU caps or paywalls and lets the team choose its host.

Photon Quantum offers a development-only free tier for 20 connected users and 60.0 GB of traffic per month, plus a free 100 CCU plan. Consider it when those defined Photon allowances suit the project better than FishNet’s host-independent model.

Photon Realtime has a development-only free plan for 20 concurrent users and 60.0 GB monthly traffic, alongside a premium option. It is an alternative for teams comparing a capped development allowance with FishNet’s uncapped concurrency policy.

Mirror Networking is a free, open-source MIT option with no paywalls or CCU costs. It is a direct alternative for teams prioritizing those terms over FishNet’s Pro additions.

Netick is free and offers server-authoritative state-sync networking for Unity; its free plan reserves interest management and lag compensation for Pro. Choose it when that free feature split better matches the project.

Normcore is another freemium alternative.

SmartFoxServer offers a Community Edition with no time limit, 100 concurrent users and full features. It may suit teams for whom that bounded community allowance is sufficient.

Colyseus offers an open-source plan for self-hosting on your own servers, with community support and no restrictions; it is an alternative for teams seeking those terms.

Browse the Game Networking Middleware category for more options.

Verdict

Choose FishNet if you are building a Unity multiplayer game and want server-authoritative networking, built-in prediction and freedom from FishNet-imposed CCU limits. Its free core is compelling for teams comfortable owning hosting choices and transport setup. Look elsewhere if primitive-only prediction colliders are a blocker, or if you need a service with its hosting and concurrency terms defined around a managed allowance.