diff --git a/web/src/components/ReconnectingBanner.tsx b/web/src/components/ReconnectingBanner.tsx
index e7a3ad01..76829771 100644
--- a/web/src/components/ReconnectingBanner.tsx
+++ b/web/src/components/ReconnectingBanner.tsx
@@ -5,6 +5,9 @@ function getReasonLabel(reason: string, t: (key: string) => string): string {
     if (reason === 'heartbeat-timeout') {
         return t('reconnecting.reason.heartbeatTimeout')
     }
+    if (reason === 'visibility-recovery') {
+        return t('reconnecting.reason.visibilityRecovery')
+    }
     if (reason === 'closed') {
         return t('reconnecting.reason.closed')
     }
diff --git a/web/src/hooks/useSSE.ts b/web/src/hooks/useSSE.ts
index 66f310d2..aa166419 100644
--- a/web/src/hooks/useSSE.ts
+++ b/web/src/hooks/useSSE.ts
@@ -596,8 +596,22 @@ export function useSSE(options: {
             requestReconnect('heartbeat-timeout')
         }, HEARTBEAT_WATCHDOG_INTERVAL_MS)
 
+        // When the tab becomes visible again, check immediately whether the
+        // SSE connection went stale while hidden (the watchdog skips checks
+        // for hidden tabs).  This avoids the user having to wait up to
+        // HEARTBEAT_WATCHDOG_INTERVAL_MS after switching back.
+        const onVisibilityChange = () => {
+            if (getVisibilityState() !== 'visible') return
+            if (eventSourceRef.current !== eventSource) return
+            if (Date.now() - lastActivityAtRef.current >= HEARTBEAT_STALE_MS) {
+                requestReconnect('visibility-recovery')
+            }
+        }
+        document.addEventListener('visibilitychange', onVisibilityChange)
+
         return () => {
             clearInterval(watchdogTimer)
+            document.removeEventListener('visibilitychange', onVisibilityChange)
             if (invalidationTimerRef.current) {
                 clearTimeout(invalidationTimerRef.current)
                 invalidationTimerRef.current = null
diff --git a/web/src/lib/locales/en.ts b/web/src/lib/locales/en.ts
index f2612610..c8eff291 100644
--- a/web/src/lib/locales/en.ts
+++ b/web/src/lib/locales/en.ts
@@ -237,6 +237,7 @@ export default {
   'reconnecting.reason.error': 'stream error',
   'reconnecting.reason.closed': 'stream closed',
   'reconnecting.reason.heartbeatTimeout': 'heartbeat timeout',
+  'reconnecting.reason.visibilityRecovery': 'resuming after background',
 
   // Send blocked
   'send.blocked.title': 'Cannot send message',
diff --git a/web/src/lib/locales/zh-CN.ts b/web/src/lib/locales/zh-CN.ts
index ea220f5a..32eaff2f 100644
--- a/web/src/lib/locales/zh-CN.ts
+++ b/web/src/lib/locales/zh-CN.ts
@@ -239,6 +239,7 @@ export default {
   'reconnecting.reason.error': '流连接错误',
   'reconnecting.reason.closed': '流连接已关闭',
   'reconnecting.reason.heartbeatTimeout': '心跳超时',
+  'reconnecting.reason.visibilityRecovery': '后台恢复中',
 
   // Send blocked
   'send.blocked.title': '无法发送消息',