diff --git a/src/sinks/websocket/sink.rs b/src/sinks/websocket/sink.rs
index 6acbf99967b43..60f0099c94884 100644
--- a/src/sinks/websocket/sink.rs
+++ b/src/sinks/websocket/sink.rs
@@ -236,6 +236,17 @@ impl WebSocketSink {
         Ok(())
     }
 
+    const fn should_encode_as_binary(&self) -> bool {
+        use codecs::encoding::Serializer::{
+            Avro, Csv, Gelf, Json, Logfmt, Native, NativeJson, RawMessage, Text,
+        };
+
+        match self.encoder.serializer() {
+            RawMessage(_) | Avro(_) | Native(_) => true,
+            Csv(_) | Logfmt(_) | Gelf(_) | Json(_) | Text(_) | NativeJson(_) => false,
+        }
+    }
+
     async fn handle_events<I, WS, O>(
         &mut self,
         input: &mut I,
@@ -261,6 +272,7 @@ impl WebSocketSink {
 
         let bytes_sent = register!(BytesSent::from(Protocol("websocket".into())));
         let events_sent = register!(EventsSent::from(Output(None)));
+        let encode_as_binary = self.should_encode_as_binary();
 
         loop {
             let result = tokio::select! {
@@ -301,7 +313,12 @@ impl WebSocketSink {
                         Ok(()) => {
                             finalizers.update_status(EventStatus::Delivered);
 
-                            let message = Message::text(String::from_utf8_lossy(&bytes));
+                            let message = if encode_as_binary {
+                                Message::binary(bytes)
+                            }
+                            else {
+                                Message::text(String::from_utf8_lossy(&bytes))
+                            };
                             let message_len = message.len();
 
                             ws_sink.send(message).await.map(|_| {