diff --git a/apps/relay/src/tunnel.ts b/apps/relay/src/tunnel.ts
index 9eeaac1ce00..bf112e63d96 100644
--- a/apps/relay/src/tunnel.ts
+++ b/apps/relay/src/tunnel.ts
@@ -2,7 +2,7 @@ import { createApiClient } from "./api-client";
 import type { TunnelHttpResponse, TunnelRequest } from "./types";
 
 type WsSocket = {
-	send: (data: string) => void;
+	send: (data: string | ArrayBuffer | Uint8Array<ArrayBuffer>) => void;
 	readyState: number;
 	close: (code?: number, reason?: string) => void;
 };
@@ -173,8 +173,15 @@ export class TunnelManager {
 				pending.resolve(msg as unknown as TunnelHttpResponse);
 			}
 		} else if (msg.type === "ws:frame") {
+			if (typeof msg.data !== "string") return;
 			const clientWs = tunnel.activeChannels.get(msg.id as string);
-			if (clientWs?.readyState === 1) clientWs.send(msg.data as string);
+			if (clientWs?.readyState === 1) {
+				if (msg.encoding === "base64") {
+					clientWs.send(Buffer.from(msg.data, "base64"));
+				} else {
+					clientWs.send(msg.data);
+				}
+			}
 		} else if (msg.type === "ws:close") {
 			const clientWs = tunnel.activeChannels.get(msg.id as string);
 			if (clientWs) {
diff --git a/packages/host-service/src/tunnel/tunnel-client.ts b/packages/host-service/src/tunnel/tunnel-client.ts
index 42d0e46771e..20a0268239e 100644
--- a/packages/host-service/src/tunnel/tunnel-client.ts
+++ b/packages/host-service/src/tunnel/tunnel-client.ts
@@ -191,9 +191,22 @@ export class TunnelClient {
 		}
 
 		const localWs = new WebSocket(wsUrl.toString());
+		localWs.binaryType = "arraybuffer";
 
 		localWs.onmessage = (event) => {
-			this.send({ type: "ws:frame", id: request.id, data: String(event.data) });
+			const data = event.data;
+			if (typeof data === "string") {
+				this.send({ type: "ws:frame", id: request.id, data });
+				return;
+			}
+			if (data instanceof ArrayBuffer) {
+				this.send({
+					type: "ws:frame",
+					id: request.id,
+					data: Buffer.from(data).toString("base64"),
+					encoding: "base64",
+				});
+			}
 		};
 
 		localWs.onclose = (event) => {
diff --git a/packages/shared/src/tunnel-protocol.ts b/packages/shared/src/tunnel-protocol.ts
index bb199865089..7bafd07dba7 100644
--- a/packages/shared/src/tunnel-protocol.ts
+++ b/packages/shared/src/tunnel-protocol.ts
@@ -20,6 +20,7 @@ export interface TunnelWsFrame {
 	type: "ws:frame";
 	id: string;
 	data: string;
+	encoding?: "base64";
 }
 
 export interface TunnelWsClose {