Free multiplayer systems let you connect players without hosting costs, but each approach trades off ease of setup against how many players you can support
The cheapest multiplayer option depends on your game's size and player count. Peer-to-peer networking costs nothing to run but works best for small groups (2 to 8 players) and requires players to have open ports or work around firewalls. Free tiers from game engines like Unreal Engine's Replication Graph or Unity's Netcode for GameObjects give you server infrastructure at no cost up to a player limit, usually 20 to 100 concurrent players depending on the service. Community-run open-source solutions like Colyseus or Mirror let you host on your own computer or a cheap VPS, shifting the cost from monthly fees to your own time setting it up.
The trade-off is always the same: free systems either limit your player count, require technical setup work, or both. A game with 500 simultaneous players cannot use peer-to-peer or a free tier—you will need paid hosting. But for indie games, prototypes, or games designed for small groups, free options work well enough that many developers never pay for multiplayer infrastructure.
Key Takeaways
- Peer-to-peer networking costs nothing but works only for 2 to 8 players and requires players to configure their network or use a relay service.
- Game engine free tiers (Unreal's Replication Graph, Unity's Netcode) provide server infrastructure at no cost up to a player limit, usually 20 to 100 concurrent players.
- Open-source frameworks like Mirror (for Unity) or Colyseus (for web games) are free but require you to host the server yourself on a computer or cheap VPS.
- Relay services like PlayFab's free tier or Gamesparks can route peer-to-peer traffic through their servers when direct connection fails, at no cost up to a usage limit.
- Your choice depends on expected player count: peer-to-peer for 2 to 8, free engine tiers for 20 to 100, and self-hosted open-source for anything larger that you want to run without paying per-player fees.
Peer-to-Peer networking for small groups
Peer-to-peer means one player's computer acts as the host and other players connect directly to it. No server sits in the middle. This costs nothing to run because you are not renting server space—the host player's internet connection carries all the game traffic.
The catch is that peer-to-peer only works smoothly when players can reach each other directly. If either player is behind a restrictive firewall or router, the connection fails. Most home networks block incoming connections by default. You can work around this with UPnP (a protocol that automatically opens ports) or by asking players to manually forward ports, but both are friction that many players will not do.
Peer-to-peer also means the host player has an advantage: their input is processed instantly while other players see a slight delay. For turn-based games or games where a 100-millisecond delay does not matter, this is fine. For fast-action games, it feels unfair.
Use peer-to-peer if your game is designed for 2 to 4 players, you control who plays (friends, not matchmaking), or you are willing to tell players to open ports. Games like Valheim and Grounded use peer-to-peer for their co-op modes because the player count is small and the audience expects to play with friends they already know.
Game engine free tiers with built-in server infrastructure
Unity and Unreal both offer free multiplayer systems that include server infrastructure at no cost up to a player limit. These are the easiest path if you are already using one of these engines.
Unity's Netcode for GameObjects and Transport are free and handle the networking code for you. You still need to choose where the server runs—you can use Unity's free Netcode Cloud (which hosts up to 20 concurrent players at no cost) or point it at your own server. Netcode Cloud is the simplest: you build your game, check a box to enable it, and players connect without you managing any infrastructure. The limit is 20 players per session, and you get a small amount of free bandwidth per month.
Unreal Engine's Replication Graph is built into the engine and handles syncing game state between players. It is free to use, but you still need a server to run on. Unreal does not provide free hosting like Unity does, so you either run the server on your own computer (works for testing and small groups), on a cheap VPS (costs $5 to $20 per month), or use a third-party service like PlayFab (which has a free tier).
Both engines also integrate with PlayFab, Microsoft's backend service. PlayFab's free tier covers up to 100,000 monthly active users and includes matchmaking, player data storage, and leaderboards. It does not include server hosting, but it handles the parts of multiplayer that are not the game simulation itself.
Open-source frameworks you host yourself
Mirror is a free, open-source networking library for Unity. It handles all the code that syncs player positions, actions, and game state. You write the game logic, Mirror handles sending that data between players. The trade-off is that you must host the server yourself.
You can run a Mirror server on your own computer while testing, or on a cheap VPS (DigitalOcean, Linode, or Vultr all offer $5 per month servers) for a live game. A $5 server can handle 50 to 100 concurrent players depending on how much data your game sends per second. Mirror is free and open-source, so there are no licensing costs, but your time setting it up and keeping it running is the cost.
Colyseus is similar but built for web-based games (games that run in a browser). It is free and open-source, and you host the server the same way—on your own computer or a cheap VPS. Colyseus handles the networking, you write the game in a web framework like Phaser or Babylon.js, and players join through a web link.
Photon PUN 2 offers a free tier with up to 20 concurrent players and 20 GB of data per month. It is not open-source, but you do not host the server—Photon does. The free tier is genuinely free with no credit card required, and it is a middle ground between "I want to host it myself" and "I want to pay nothing and have someone else handle it." If you exceed the free tier limits, Photon charges per concurrent player.
Relay services for peer-to-peer with fallback
A relay service sits between two players and forwards their messages when they cannot connect directly. This solves the firewall problem with peer-to-peer: if direct connection fails, traffic goes through the relay instead.
PlayFab Multiplayer Servers includes a free relay tier. Gamesparks (also by Amazon) offers free relay for peer-to-peer games. Steam Networking (part of Steamworks, free to use if your game is on Steam) includes relay built in and handles peer-to-peer connections automatically, falling back to relay when needed.
The advantage is that you keep the low latency of peer-to-peer when it works, but players behind firewalls can still join. The disadvantage is that relay adds a small amount of latency (usually 10 to 50 milliseconds extra) and uses bandwidth from the relay service's quota. Most free tiers limit relay to a certain amount of data per month, so this works for small games but not for high-traffic games.
If your game is on Steam, use Steam Networking—it is free, it is built into Steamworks, and it handles relay automatically. If your game is not on Steam, PlayFab or Gamesparks relay is the next easiest option.
Comparing the options by player count and setup time
| Approach | Player Limit | Setup Time | Hosting Cost | Best For |
|---|---|---|---|---|
| Peer-to-peer | 2–8 | Low (built into most engines) | $0 | Small co-op games, friends only |
| Peer-to-peer + relay | 2–8 | Low to medium | $0 (free tier) | Small games where players may be behind firewalls |
| Engine free tier (Unity Netcode Cloud) | 20 | Very low | $0 | Quick prototypes, small multiplayer games |
| Photon PUN 2 free tier | 20 | Low | $0 | Small games, no server hosting wanted |
| Open-source (Mirror, Colyseus) | 50–200+ | High (requires server setup) | $5–20/month for VPS | Larger indie games, developers comfortable with servers |
| PlayFab backend only | Unlimited (you host server) | Medium | $0 (free tier) or your server cost | Games needing matchmaking, leaderboards, player data |
What to do if free options hit their limits
If your game grows beyond what free tiers support, you have two paths: pay for a higher tier of the service you are already using, or switch to a paid provider.
Most free services scale up smoothly. Unity Netcode Cloud charges per concurrent player above 20. Photon charges per concurrent player above 20. PlayFab charges based on usage. These are usually cheaper than starting fresh with a new provider, so if you have already built your game on a free tier, upgrading is often the path of least resistance.
If you are using an open-source framework like Mirror, you can upgrade your VPS to a larger machine (costs $10 to $50 per month) or move to a dedicated game server host like GameServers.com or Nitrado. These hosts charge per slot (per concurrent player), usually $0.50 to $2 per player per month, but they handle scaling and backups for you.
The key is to choose a free option that can scale to your paid option without rewriting your networking code. If you start with peer-to-peer and then need 100 players, you will have to rewrite. If you start with Mirror or Photon, you can keep the same code and just pay for more capacity.
Frequently Asked Questions
Can I use peer-to-peer if some players are behind firewalls?
Direct peer-to-peer will not work. You need a relay service to forward traffic through a server when direct connection fails. Steam Networking, PlayFab relay, or Gamesparks relay all do this automatically. The trade-off is a small amount of added latency (usually 10 to 50 milliseconds) when relay is in use.
What is the difference between hosting a server myself and using a free tier?
A free tier means someone else (Unity, Photon, PlayFab) runs the server and you pay nothing up to a limit. Hosting yourself means you run the server on your own computer or a VPS you pay for, but you have full control and no player limit (only your server's capacity). Free tiers are easier to start with; self-hosting is cheaper at scale.
Do I need to pay for multiplayer if my game is on Steam?
No. Steam Networking is free and built into Steamworks. It handles peer-to-peer connections with automatic relay fallback. You only need to integrate Steamworks into your game, which most engines support natively.
How many players can a $5 per month VPS actually handle?
It depends on how much data your game sends per second. A simple game (turn-based, low update rate) can handle 100+ players. A fast-action game (frequent position updates, lots of events) might handle 20 to 50. The only way to know is to test with your actual game code and see when the server's CPU or bandwidth maxes out.
What happens to my game if a free service shuts down or changes its pricing?
If you are using a proprietary service (Photon, PlayFab), you are dependent on that company's decisions. If you are using open-source (Mirror, Colyseus), you own the code and can keep running it on your own server forever. This is one reason some developers prefer open-source even if it requires more setup work.