Colyseus is an open-source framework for writing your own authoritative game server in Node.js. GameRelay is a hosted service where you write no server at all. Both are good choices for web games. Which one fits depends on whether you want to write and run that server.
The short version
| GameRelay | Colyseus | |
|---|---|---|
| Server code | None | You write room classes in Node.js (TypeScript) and deploy them |
| Who runs the rules | A host player's browser; our server relays, orders and limits messages | Your server: fully authoritative |
| Syncing state | Entities with owners, smoothed for you; events, requests, claims, inputs | A schema-based state on the server, sent to clients as binary deltas |
| Hosting | Hosted by us | Self-host anywhere, or Colyseus Cloud |
| Clients | JavaScript and TypeScript in the browser | JavaScript, Unity, Godot, GameMaker, Defold, Construct, Haxe |
| Built in | Rooms, quick match, parties, chat, saves, leaderboards, webhooks, MCP servers | Rooms, matchmaking, reconnection, scaling with Redis; the rest you build on your server |
| Pricing | Free plan (1 game, 16 players online), Basic at $3.99/month | Free to self-host (you pay for the servers); Colyseus Cloud from $15/month, with no player limits |
| Open source | The SDK (MIT) | All of it (MIT) |
The real difference: who decides
In Colyseus, your server runs the game. Players send inputs, your room code decides what happens, and nobody can change the result from their browser. That's the strongest protection against cheating, and you can put any logic you like on the server. The cost is a backend to write, deploy, monitor and keep up to date.
In GameRelay, one player's browser is the host. Each player writes their own avatar, and the host runs the shared world. If the host leaves, another player takes over with the same state. Our server orders and limits every message and stamps it with the sender, so players can't pretend to be each other. It doesn't run your rules, though, so a determined player could still bend their own game. For most casual, co-op and party games that trade is worth it: there is nothing to deploy.
Choose Colyseus when
- Cheating matters: competitive or ranked play, or anything with real-money value.
- You want game logic on a server you control, or to self-host with no vendor at all.
- Your game ships on Unity, Godot or other engines besides the web.
- You're comfortable running a Node.js service, or happy to pay for Colyseus Cloud to run it.
Choose GameRelay when
- You don't want a backend: no server code, no deploys, no scaling.
- Your game is casual, co-op or social, where host-run rules are enough.
- You want lobbies, parties, chat, saves and leaderboards without building them.
- An AI assistant writes your code. A model is far more reliable at a single HTML file than at a client and a server that must agree.
Sources
Checked on October 3, 2026 from colyseus.io/pricing, the Colyseus repository and its documentation. Products change; if something here is out of date, tell us at support@gamerelay.io and we'll fix it.
Try it
GameRelay has a free plan, no card needed. Get a public key, then follow the quickstart, or point your AI coding agent at llms.txt.