what-happens-when-a-user-joins-a-room-at-maximum-capacity.mdx

---
meta:
  title: "What happens when a user joins a room at maximum capacity?"
  description:
    "Learn what happens when a room reaches the maximum simultaneous connections
    per room"
---

Liveblocks allows you to gracefully handle maximum user limits in rooms. But
first, when is a room at maximum capacity?

- A room is full when it’s hit your maximum simultaneous connections per room
  limit.
- Your maximum simultaneous connections limit is defined by your current
  [plan](/pricing).
- Any users above that count will not be able to join the room.
- Any users already in the room will not be affected by another user trying to
  join.
- If a user can’t join a room, they will not be counted towards your MAUs.

## Example

For example, let’s say your plan allows for 50 simultaneous connections. If
there’s a room that currently has 50 users inside, Marie (the 51st user) will
not be able to join the room. If Marie tries to join, the first 50 users in the
room will be unaffected, and the room will function as normal. However, Marie’s
client will receive an error, which can be handled.

## Handling users that are over the count

No JavaScript `Error` is thrown when a user tries to join a room that’s full,
instead you can listen for error events, which are helpful for displaying a
warning or redirecting the user elsewhere.

### In React

With our
[`@liveblocks/react`](https://liveblocks.io/docs/api-reference/liveblocks-react)
package, you can listen for error events with
[`useErrorListener`](/docs/api-reference/liveblocks-react#useErrorListener).
When `error.code === 4005`, that means the room was full when the user tried to
join.

```tsx highlight="15-17"
import { useErrorListener } from "../liveblocks.config";

function App() {
  // Listen for errors
  useErrorListener((error) => {
    switch (error.code) {
      case -1:
        // Authentication error
        break;

      case 4001:
        // Could not connect because you don't have access to this room
        break;

      case 4005:
        // Could not connect because room was full
        break;

      default:
        // Unexpected error
        break;
    }
  });

  // ...
}
```

### In JavaScript

With our [`@liveblocks/client`](/docs/api-reference/liveblocks-client) package,
you can listen for error events with
[`room.subscribe("error")`](/docs/api-reference/liveblocks-client#Room.subscribe.error).
When `error.code === 4005`, that means the room was full when the user tried to
join.

```ts highlight="17-19"
// No error is thrown when the room is full
const { room, leave } = client.enterRoom("my-room", {
  /* ... */
});

// Listen for errors
const unsubscribe = room.subscribe("error", (error) => {
  switch (error.code) {
    case -1:
      // Authentication error
      break;

    case 4001:
      // Could not connect because you don't have access to this room
      break;

    case 4005:
      // Could not connect because room was full
      break;

    default:
      // Unexpected error
      break;
  }
});
```