diff --git a/app/webview/[slug].tsx b/app/webview/[slug].tsx
index 5b1e7f0..8561912 100644
--- a/app/webview/[slug].tsx
+++ b/app/webview/[slug].tsx
@@ -143,6 +143,7 @@ export default function WebViewScreen() {
   };
 
   const { handleMessage } = useWebViewMessageHandler({
+    host: 'webview_slug',
     onNavigateBack: handleBack,
     onNavigateWebview: handleNavigateWebview,
   });
diff --git a/constants/eventname.ts b/constants/eventname.ts
index ae8a21b..668ec7a 100644
--- a/constants/eventname.ts
+++ b/constants/eventname.ts
@@ -18,4 +18,9 @@ export const PAGE_VIEW_EVENT = {
   MAIN_PAGE: 'MainPage',
   SUBSCRIBE_PAGE: 'SubscribePage',
   MORE_PAGE: 'MorePage',
-}
\ No newline at end of file
+}
+
+// 앱 자체 진단용 — 사용자 행동이 아니라 웹↔앱 브리지 상태를 관측한다.
+export const DIAGNOSTIC_EVENT = {
+  BRIDGE_UNKNOWN_MESSAGE: 'Bridge UnknownMessage',
+}
diff --git a/hooks/use-webview-message-handler.ts b/hooks/use-webview-message-handler.ts
index 4b7143f..19ff45b 100644
--- a/hooks/use-webview-message-handler.ts
+++ b/hooks/use-webview-message-handler.ts
@@ -1,8 +1,11 @@
 import { WebViewMessage, WebViewMessageEvent, WebViewMessageTypes } from '@/types/webview-message.types';
+import { reportUnknownBridgeMessage } from '@/utils/webview';
 import { useCallback } from 'react';
 import { Linking } from 'react-native';
 
 interface UseWebViewMessageHandlerOptions {
+  /** 처리되지 않은 메시지를 어느 화면이 받았는지 구분하기 위한 이름 */
+  host: string;
   // 뒤로가기 요청 시 호출
   onNavigateBack?: () => void;
   // 웹뷰 내 화면 이동 요청 시 호출
@@ -21,6 +24,7 @@ interface UseWebViewMessageHandlerOptions {
 
 // WebView 메시지를 처리하는 Hook
 export const useWebViewMessageHandler = ({
+  host,
   onNavigateBack,
   onNavigateWebview,
   onSubscribe,
@@ -83,12 +87,13 @@ export const useWebViewMessageHandler = ({
           );
           break;
         default:
-          console.warn('[WebViewHandler] 알 수 없는 메시지 타입:', message);
+          reportUnknownBridgeMessage((message as { type?: unknown }).type, host);
       }
     } catch (error) {
       console.error('[WebViewHandler] 메시지 파싱 오류:', error);
     }
   }, [
+    host,
     onNavigateBack,
     onNavigateWebview,
     onSubscribe,
diff --git a/ui/club-detail/club-detail-screen.tsx b/ui/club-detail/club-detail-screen.tsx
index 5e6893f..f3adf0f 100644
--- a/ui/club-detail/club-detail-screen.tsx
+++ b/ui/club-detail/club-detail-screen.tsx
@@ -124,6 +124,7 @@ export default function ClubWebViewScreen() {
 
   // WebView 메시지 핸들러
   const { handleMessage } = useWebViewMessageHandler({
+    host: 'club_detail',
     onNavigateBack: handleBack,
     onSubscribe: async (targetId: string, clubName?: string) => {
       trackEvent(USER_EVENT.SUBSCRIBE_BUTTON_CLICKED, {
diff --git a/ui/home/home-webview-screen.tsx b/ui/home/home-webview-screen.tsx
index ae70c3f..392171b 100644
--- a/ui/home/home-webview-screen.tsx
+++ b/ui/home/home-webview-screen.tsx
@@ -2,7 +2,7 @@ import { useHomeWebViewPreloadContext } from '@/contexts/home-webview-preload-co
 import { useMixpanelContext } from '@/contexts/mixpanel-context';
 import { useSubscribedClubsContext } from '@/contexts/subscribed-clubs-context';
 import { ensureAccessToken } from '@/services/auth-token.service';
-import { appendSessionId, buildStudentTokenInjection, getWebViewUserAgent, isWebViewOrigin } from '@/utils/webview';
+import { appendSessionId, buildStudentTokenInjection, getWebViewUserAgent, isWebViewOrigin, reportUnknownBridgeMessage } from '@/utils/webview';
 import Constants from 'expo-constants';
 import { useRouter } from 'expo-router';
 import * as WebBrowser from 'expo-web-browser';
@@ -145,6 +145,9 @@ export function HomeWebViewScreen({ onError }: HomeWebViewScreenProps) {
               payload: { version: Constants.expoConfig?.version ?? 'unknown' },
             });
             break;
+
+          default:
+            reportUnknownBridgeMessage(type, 'home');
         }
       } catch {
         // 파싱 실패 무시
diff --git a/utils/webview.ts b/utils/webview.ts
index 35cb69b..e50721b 100644
--- a/utils/webview.ts
+++ b/utils/webview.ts
@@ -1,3 +1,5 @@
+import { DIAGNOSTIC_EVENT } from '@/constants/eventname';
+import { getMixpanel } from '@/utils/mixpanel';
 import Constants from 'expo-constants';
 import { Platform } from 'react-native';
 
@@ -53,3 +55,24 @@ export const buildStudentTokenInjection = (
          window.__MOADONG_STUDENT_TOKEN__ = ${JSON.stringify(token)};
        })(); true;`;
 };
+
+// 웹이 앱보다 앞서 나가 새 메시지를 추가했는데 호스트가 그걸 모르는 상황을 관측한다.
+// 각 호스트 switch의 default에서만 부르므로, 그 호스트가 실제로 처리하지 못한 것만 잡힌다.
+// 리포팅 실패가 메시지 처리를 막아선 안 되므로 예외를 밖으로 내보내지 않는다.
+export const reportUnknownBridgeMessage = (type: unknown, host: string): void => {
+  // 서드파티가 쏜 비정형 메시지를 걸러내기 위해 문자열 type만 취급한다.
+  if (typeof type !== 'string') return;
+
+  console.warn(`[WebViewBridge] 처리되지 않은 메시지: ${type} (host: ${host})`);
+
+  getMixpanel()
+    .then(mixpanel =>
+      mixpanel?.track(DIAGNOSTIC_EVENT.BRIDGE_UNKNOWN_MESSAGE, {
+        message_type: type,
+        host,
+        app_version: Constants.expoConfig?.version || '1.0.0',
+        platform: Platform.OS,
+      }),
+    )
+    .catch(err => console.error('[WebViewBridge] 리포팅 실패:', err));
+};