SmartFoxServer
A comprehensive SDK for rapidly developing multiplayer games and applications
About SmartFoxServer
SmartFoxServer is middleware for building large-scale multiplayer games, MMOs, and virtual communities. Born in 2004 and developed by gotoAndPlay(), it provides a real-time server engine with client SDKs for Unity, Godot, HTML5, iOS, Android, Java, C++ and more, scaling to tens of thousands of concurrent users.
Pros & Cons
Pros
- Mature, battle-tested engine in production since 2004 powering hundreds of multiplayer titles
- Free Community Edition lets you build full applications and prototypes at no cost
- Broad client SDK coverage including Unity, Godot, HTML5 and mobile
- Scales to tens of thousands of concurrent users with an optimized binary protocol
- Strong documentation, many example projects, and an active support forum
Cons
- Self-hosted server requires DevOps work to deploy, scale, and maintain
- Server-side extensions are primarily Java, which has a learning curve
- Per-CCU licensing can get expensive for very large concurrent player bases
- Pricing is in euros and oriented toward studios rather than hobbyists once you exceed the free tier
Key Features
Real-time server engine
Optimized communication protocol that scales to tens of thousands of concurrent users for real-time and turn-based multiplayer.
Multi-platform client SDKs
Official APIs for Unity, Godot, HTML5/JavaScript, iOS, Android, Java, C++, UWP and Adobe Flash/Flex/Air.
Game API & room management
Built-in lobby, game rooms, matchmaking, and a high-level Game API for rapid multiplayer development.
Buddy List API
Friend lists, presence, and social features for building communities and persistent virtual worlds.
Server-side extensions
Write custom authoritative game logic in Java (or JavaScript/Python via add-ons) running directly on the server.
Administration tools
AdminTool dashboard for monitoring users, rooms, zones, and server health in real time.
Database & persistence
Built-in database connectivity and data persistence for profiles, rankings, and saved game state.
Extensive documentation & examples
Large documentation set, dozens of example projects with full source, and an active support forum.
Pricing
- Full SmartFoxServer 3 feature set
- Build prototypes and applications
- All client SDKs
- Community forum support
- From 500 CCU (prepaid rechargeable credit, charged daily)
- Adjustable CCU and add-ons anytime
- Unlimited apps, no MAU limit
- Volume discounts (30-55%) at higher CCU
- Free software updates
- One month direct email support
- From 500 CCU, runs on one machine
- One-time fee, everlasting license
- Upgrade by paying the price difference
- Unlimited apps, no MAU limit
- Free software updates
- Perpetual online forum support
Best For
Real-time multiplayer games
Build action, racing, or MMO games with authoritative server-side logic and low-latency state sync.
Turn-based and card/board games
Power matchmaking, rooms, and turn management for poker, chess, and casino-style titles.
Virtual worlds and communities
Run persistent social spaces with buddy lists, chat, profiles, and presence.
Cross-platform Unity/Godot backends
Add networking to Unity or Godot projects across desktop, mobile, and web with a single server backend.
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