PartyKit joined Cloudflare in 2024. Today it's PartyServer, a library for writing real-time servers on Cloudflare Durable Objects, and PartySocket, a client. It's a toolkit for building any real-time app. GameRelay is a finished backend for multiplayer games, with nothing to deploy.
The short version
| GameRelay | PartyKit / PartyServer | |
|---|---|---|
| Server code | None | You write a server class per room and deploy it to your Cloudflare account |
| Made for | Multiplayer browser games | Any real-time app: collaboration, chat, games |
| Syncing state | Entities with owners, smoothed for you; host handover built in | Whatever your server sends; Yjs support for shared documents |
| Game features | Rooms, quick match, room lists, parties, chat, saves, leaderboards, webhooks | None built in: you build lobbies, matchmaking and storage with Workers and Durable Objects |
| Hosting | Hosted by us | Your Cloudflare account, on its global network |
| Pricing | Free plan (1 game, 16 players online), Basic at $3.99/month | Cloudflare's usage pricing: a free tier, then Workers Paid from $5/month plus requests and duration |
| Open source | The SDK (MIT) | Yes (ISC) |
A toolkit versus a game backend
PartyServer gives you a stateful server for each room, close to your players, with WebSockets and storage. That's a great foundation, and you decide everything above it: the message format, who runs the game, how players are matched, how state reaches late joiners and how movement is smoothed.
GameRelay makes those decisions for you, for games. Players get rooms, quick match and parties; the SDK syncs entities, smooths them and hands the host role over when a player leaves; scores, saves and chat are calls on the client. You give up control of the server, and you don't have one to write.
Pricing
On Cloudflare you pay for what your Durable Objects use: requests (incoming WebSocket messages count at 20 to 1) and time, after a free tier, with Workers Paid at $5 a month minimum. That can be very cheap, but it depends on your code. GameRelay's plans are flat: see our plans and Durable Objects pricing.
Choose PartyKit when
- You want server-side logic, written your way, on Cloudflare's edge.
- Your app is more than a game: collaborative editing, presence, shared documents.
- You already use Cloudflare Workers and want everything in one account.
Choose GameRelay when
- You're making a game and want game features, not building blocks.
- You don't want to write, deploy or debug a server.
- An AI assistant writes your code: one HTML file with the GameRelay SDK, nothing to deploy.
Sources
Checked on October 3, 2026 from PartyKit's announcement, the cloudflare/partykit repository and Cloudflare's pricing. 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.