diff --git a/src/client/LobbySocket.ts b/src/client/LobbySocket.ts
index 4e4922508..909964a85 100644
--- a/src/client/LobbySocket.ts
+++ b/src/client/LobbySocket.ts
@@ -1,5 +1,9 @@
 import { getServerConfigFromClient } from "../core/configuration/ConfigLoader";
-import { PublicGames, PublicGamesSchema } from "../core/Schemas";
+import {
+  LobbyCountsSchema,
+  PublicGames,
+  PublicGamesSchema,
+} from "../core/Schemas";
 
 interface LobbySocketOptions {
   reconnectDelay?: number;
@@ -19,6 +23,7 @@ export class PublicLobbySocket {
   private wsAttemptCounted = false;
   private workerPath: string = "";
   private stopped = true;
+  private lastGames: PublicGames | null = null;
 
   private readonly reconnectDelay: number;
   private readonly maxWsAttempts: number;
@@ -79,10 +84,30 @@ export class PublicLobbySocket {
 
   private handleMessage(event: MessageEvent) {
     try {
-      const publicGames = PublicGamesSchema.parse(
-        JSON.parse(event.data as string),
-      );
-      this.onLobbiesUpdate(publicGames);
+      const raw = JSON.parse(event.data as string);
+
+      // Slim update — just counts/timers, merge into cached full state.
+      const counts = LobbyCountsSchema.safeParse(raw);
+      if (counts.success && this.lastGames) {
+        const games = {} as PublicGames["games"];
+        for (const [type, lobbies] of Object.entries(this.lastGames.games) as [
+          keyof PublicGames["games"],
+          PublicGames["games"][keyof PublicGames["games"]],
+        ][]) {
+          games[type] = lobbies.map((lobby) => {
+            const update = counts.data.counts[lobby.gameID];
+            return update ? { ...lobby, ...update } : lobby;
+          }) as PublicGames["games"][typeof type];
+        }
+        this.onLobbiesUpdate({ serverTime: counts.data.serverTime, games });
+        this.lastGames = { serverTime: counts.data.serverTime, games };
+        return;
+      }
+
+      // Full update — store and forward.
+      const incoming = PublicGamesSchema.parse(raw);
+      this.lastGames = incoming;
+      this.onLobbiesUpdate(incoming);
     } catch (error) {
       console.error("Error parsing WebSocket message:", error);
       if (this.ws && this.ws.readyState === WebSocket.OPEN) {
diff --git a/src/core/Schemas.ts b/src/core/Schemas.ts
index 07b7f263e..abe37d3df 100644
--- a/src/core/Schemas.ts
+++ b/src/core/Schemas.ts
@@ -169,6 +169,16 @@ export const PublicGamesSchema = z.object({
   games: z.record(PublicGameTypeSchema, z.array(PublicGameInfoSchema)),
 });
 
+// Slim update sent when game configs haven't changed — just player counts + timers.
+export const LobbyCountsSchema = z.object({
+  serverTime: z.number(),
+  counts: z.record(
+    z.string(), // gameID
+    z.object({ numClients: z.number(), startsAt: z.number().optional() }),
+  ),
+});
+export type LobbyCounts = z.infer<typeof LobbyCountsSchema>;
+
 export class LobbyInfoEvent implements GameEvent {
   constructor(
     public lobby: GameInfo,
diff --git a/src/server/MasterLobbyService.ts b/src/server/MasterLobbyService.ts
index 9285b8a91..0bffa1937 100644
--- a/src/server/MasterLobbyService.ts
+++ b/src/server/MasterLobbyService.ts
@@ -75,7 +75,7 @@ export class MasterLobbyService {
     if (this.readyWorkers.size === this.config.numWorkers() && !this.started) {
       this.started = true;
       this.log.info("All workers ready, starting game scheduling");
-      startPolling(async () => this.broadcastLobbies(), 500);
+      startPolling(async () => this.broadcastLobbies(), 250);
       startPolling(async () => await this.maybeScheduleLobby(), 1000);
     }
   }
diff --git a/src/server/WorkerLobbyService.ts b/src/server/WorkerLobbyService.ts
index ab8852968..8e6bba496 100644
--- a/src/server/WorkerLobbyService.ts
+++ b/src/server/WorkerLobbyService.ts
@@ -1,6 +1,6 @@
 import http from "http";
 import { WebSocket, WebSocketServer } from "ws";
-import { PublicGameInfo, PublicGames } from "../core/Schemas";
+import { LobbyCounts, PublicGameInfo, PublicGames } from "../core/Schemas";
 import { GameManager } from "./GameManager";
 import {
   MasterMessageSchema,
@@ -12,6 +12,8 @@ import { logger } from "./Logger";
 export class WorkerLobbyService {
   private readonly lobbiesWss: WebSocketServer;
   private readonly lobbyClients: Set<WebSocket> = new Set();
+  private lastPublicGames: PublicGames | null = null;
+  private lastGameSetKey: string = "";
 
   constructor(
     private readonly server: http.Server,
@@ -112,6 +114,10 @@ export class WorkerLobbyService {
   private setupLobbiesWebSocket() {
     this.lobbiesWss.on("connection", (ws: WebSocket) => {
       this.lobbyClients.add(ws);
+      // Send the last known full state immediately on connect.
+      if (this.lastPublicGames && ws.readyState === WebSocket.OPEN) {
+        ws.send(JSON.stringify(this.lastPublicGames));
+      }
       ws.on("message", () => {
         ws.terminate();
       });
@@ -136,8 +142,39 @@ export class WorkerLobbyService {
     });
   }
 
+  private buildCountsMessage(publicGames: PublicGames): string {
+    const counts: LobbyCounts["counts"] = {};
+    for (const lobbies of Object.values(publicGames.games)) {
+      for (const lobby of lobbies) {
+        counts[lobby.gameID] = {
+          numClients: lobby.numClients,
+          startsAt: lobby.startsAt,
+        };
+      }
+    }
+    return JSON.stringify({
+      serverTime: publicGames.serverTime,
+      counts,
+    } satisfies LobbyCounts);
+  }
+
   private broadcastLobbiesToClients(publicGames: PublicGames) {
-    const message = JSON.stringify(publicGames);
+    const allLobbies = Object.values(publicGames.games).flat();
+    const gameSetKey = allLobbies
+      .map((g) => g.gameID)
+      .sort()
+      .join(",");
+
+    const configsChanged = gameSetKey !== this.lastGameSetKey;
+    this.lastGameSetKey = gameSetKey;
+
+    if (configsChanged) {
+      this.lastPublicGames = publicGames;
+    }
+
+    const message = configsChanged
+      ? JSON.stringify(publicGames)
+      : this.buildCountsMessage(publicGames);
 
     const clientsToRemove: WebSocket[] = [];
     this.lobbyClients.forEach((client) => {