diff --git a/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/client/ClientPeriodicStdinScanner.java b/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/client/ClientPeriodicStdinScanner.java
index aa19daa..d49a565 100644
--- a/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/client/ClientPeriodicStdinScanner.java
+++ b/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/client/ClientPeriodicStdinScanner.java
@@ -56,7 +56,7 @@ public class ClientPeriodicStdinScanner implements Handler<Long> {
                         Buffer b = Buffer.buffer(len);
                         b = b.appendBytes(clientPayload, prevIdx, len);
                         b = b.appendByte((byte)'\n');
-                        webSocket.writeTextMessage(b.toString(StandardCharsets.UTF_8));
+                        webSocket.writeBinaryMessage(b);
                         prevIdx = idx + eolLength;
                     }
                 } while (idx >= 0 && prevIdx < clientPayload.length);
diff --git a/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/client/WebsocketClientParticle.java b/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/client/WebsocketClientParticle.java
index 1dd2583..2ddc0a4 100644
--- a/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/client/WebsocketClientParticle.java
+++ b/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/client/WebsocketClientParticle.java
@@ -56,7 +56,7 @@ public class WebsocketClientParticle extends AbstractVerticle {
         ));
 
         webSocket
-                .textMessageHandler(msg -> logger.info("Got message: {}", msg))
+                .binaryMessageHandler(msg -> logger.info("Got message: {}", msg))
                 .closeHandler(unused -> {
                     try {
                         stop();
diff --git a/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/server/WebsocketServerHandler.java b/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/server/WebsocketServerHandler.java
index 6a21e19..75c952c 100644
--- a/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/server/WebsocketServerHandler.java
+++ b/2024/08/chat_demo1/chat_demo1_web/src/main/java/ch/polgrabia/demos/server/WebsocketServerHandler.java
@@ -2,31 +2,33 @@ package ch.polgrabia.demos.server;
 
 import ch.polgrabia.demos.client.WebsocketClientApp;
 import io.vertx.core.Handler;
+import io.vertx.core.buffer.Buffer;
 import io.vertx.core.http.ServerWebSocket;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class WebsocketServerHandler implements Handler<ServerWebSocket> {
-    private static final Logger logger = LoggerFactory.getLogger(WebsocketClientApp.class);
+    private static final Logger logger = LoggerFactory.getLogger(WebsocketServerHandler.class);
 
     @Override
     public void handle(ServerWebSocket serverWebSocket) {
-        serverWebSocket.writeTextMessage("Hello");
-        serverWebSocket.textMessageHandler(new WebsocketTextMessageHandler(serverWebSocket));
+        serverWebSocket.writeBinaryMessage(Buffer.buffer("Hello"));
+        serverWebSocket.handler(new WebsocketMessageHandler(serverWebSocket));
     }
 
-    static class WebsocketTextMessageHandler implements Handler<String> {
+    static class WebsocketMessageHandler implements Handler<Buffer> {
 
         private final ServerWebSocket serverWebSocket;
 
-        public WebsocketTextMessageHandler(ServerWebSocket serverWebSocket) {
+        public WebsocketMessageHandler(ServerWebSocket serverWebSocket) {
             this.serverWebSocket = serverWebSocket;
+            this.serverWebSocket.setWriteQueueMaxSize(0);
         }
 
         @Override
-        public void handle(String s) {
+        public void handle(Buffer s) {
             logger.info("Got message {}", s);
-            serverWebSocket.writeTextMessage("Pong: " + s); // TBD send to kafka
+            serverWebSocket.writeBinaryMessage(Buffer.buffer("Pong: " + s.toString() + "\n")); // TBD send to kafka
         }
     }