diff --git a/web-ui/src/lib/hooks/useAlerts.ts b/web-ui/src/lib/hooks/useAlerts.ts
index 025391f..0f2f9b1 100644
--- a/web-ui/src/lib/hooks/useAlerts.ts
+++ b/web-ui/src/lib/hooks/useAlerts.ts
@@ -4,11 +4,13 @@ import useSWR from 'swr';
 import { Server } from '@/src/types/server';
 import { AlertRulesResponse, AlertingInfoResponse, WebhookDeliveriesResponse } from '@/src/types/alerts';
 import { getClient } from '@/src/lib/api/client';
+import { usePageVisibility } from './usePageVisibility';
 
 /**
  * Hook for fetching alert rules
  */
 export function useAlerts(server: Server | null) {
+  const isVisible = usePageVisibility();
   const fetcher = async (): Promise<AlertRulesResponse> => {
     if (!server) throw new Error('No server');
     const client = getClient(server);
@@ -21,7 +23,7 @@ export function useAlerts(server: Server | null) {
     swrKey,
     fetcher,
     {
-      refreshInterval: 30000,
+      refreshInterval: isVisible ? 30000 : 0,
       revalidateOnFocus: true,
       dedupingInterval: 5000,
     }
@@ -39,6 +41,7 @@ export function useAlerts(server: Server | null) {
  * Hook for fetching alerting system info
  */
 export function useAlertingInfo(server: Server | null) {
+  const isVisible = usePageVisibility();
   const fetcher = async (): Promise<AlertingInfoResponse> => {
     if (!server) throw new Error('No server');
     const client = getClient(server);
@@ -51,7 +54,7 @@ export function useAlertingInfo(server: Server | null) {
     swrKey,
     fetcher,
     {
-      refreshInterval: 60000,
+      refreshInterval: isVisible ? 60000 : 0,
       revalidateOnFocus: true,
       dedupingInterval: 10000,
     }
@@ -69,6 +72,7 @@ export function useAlertingInfo(server: Server | null) {
  * Hook for fetching webhook delivery history
  */
 export function useWebhookDeliveries(server: Server | null) {
+  const isVisible = usePageVisibility();
   const fetcher = async (): Promise<WebhookDeliveriesResponse> => {
     if (!server) throw new Error('No server');
     const client = getClient(server);
@@ -81,7 +85,7 @@ export function useWebhookDeliveries(server: Server | null) {
     swrKey,
     fetcher,
     {
-      refreshInterval: 30000,
+      refreshInterval: isVisible ? 30000 : 0,
       revalidateOnFocus: true,
       dedupingInterval: 5000,
     }
diff --git a/web-ui/src/lib/hooks/useAudit.ts b/web-ui/src/lib/hooks/useAudit.ts
index 43500e1..e42eea0 100644
--- a/web-ui/src/lib/hooks/useAudit.ts
+++ b/web-ui/src/lib/hooks/useAudit.ts
@@ -4,11 +4,13 @@ import useSWR from 'swr';
 import { Server } from '@/src/types/server';
 import { AuditLogsResponse, AuditLogsParams } from '@/src/types/audit';
 import { getClient } from '@/src/lib/api/client';
+import { usePageVisibility } from './usePageVisibility';
 
 /**
  * Hook for fetching audit logs with filtering and pagination
  */
 export function useAudit(server: Server | null, params?: AuditLogsParams) {
+  const isVisible = usePageVisibility();
   const fetcher = async (): Promise<AuditLogsResponse> => {
     if (!server) throw new Error('No server');
     const client = getClient(server);
@@ -24,7 +26,7 @@ export function useAudit(server: Server | null, params?: AuditLogsParams) {
     swrKey,
     fetcher,
     {
-      refreshInterval: 30000, // 30s refresh
+      refreshInterval: isVisible ? 30000 : 0, // 30s refresh (paused when tab hidden)
       revalidateOnFocus: true,
       dedupingInterval: 5000,
     }
diff --git a/web-ui/src/lib/hooks/useContainers.ts b/web-ui/src/lib/hooks/useContainers.ts
index c7704e6..3f89c72 100644
--- a/web-ui/src/lib/hooks/useContainers.ts
+++ b/web-ui/src/lib/hooks/useContainers.ts
@@ -7,6 +7,7 @@ import { Server } from '@/src/types/server';
 import { getClient, CoreService } from '@/src/lib/api/client';
 import { useEventStream } from '@/src/lib/events/useEventStream';
 import { ServerEvent, isContainerEvent, ConnectionStatus } from '@/src/types/events';
+import { usePageVisibility } from './usePageVisibility';
 
 export interface CreateContainerProgress {
   state: string;
@@ -17,6 +18,7 @@ export interface CreateContainerProgress {
  * Hook for managing containers for a specific server
  */
 export function useContainers(server: Server | null) {
+  const isVisible = usePageVisibility();
   // Create a stable fetcher for this server
   const fetcher = async (): Promise<Container[]> => {
     if (!server) return [];
@@ -71,7 +73,7 @@ export function useContainers(server: Server | null) {
     systemInfoKey,
     systemInfoFetcher,
     {
-      refreshInterval: 60000, // Refresh every minute
+      refreshInterval: isVisible ? 60000 : 0, // Refresh every minute (paused when tab hidden)
       revalidateOnFocus: false,
       dedupingInterval: 30000,
     }
@@ -93,7 +95,7 @@ export function useContainers(server: Server | null) {
     coreServicesKey,
     coreServicesFetcher,
     {
-      refreshInterval: 30000, // Refresh every 30s
+      refreshInterval: isVisible ? 30000 : 0, // Refresh every 30s (paused when tab hidden)
       revalidateOnFocus: true,
       dedupingInterval: 10000,
     }
diff --git a/web-ui/src/lib/hooks/useMetrics.ts b/web-ui/src/lib/hooks/useMetrics.ts
index 40c60ea..c8b7e6f 100644
--- a/web-ui/src/lib/hooks/useMetrics.ts
+++ b/web-ui/src/lib/hooks/useMetrics.ts
@@ -5,6 +5,7 @@ import useSWR from 'swr';
 import { ContainerMetrics, ContainerMetricsWithRate } from '@/src/types/container';
 import { Server } from '@/src/types/server';
 import { getClient } from '@/src/lib/api/client';
+import { usePageVisibility } from './usePageVisibility';
 
 interface MetricsSnapshot {
   metrics: Record<string, ContainerMetrics>;
@@ -15,6 +16,7 @@ interface MetricsSnapshot {
  * Hook for fetching container metrics with polling and CPU rate calculation
  */
 export function useMetrics(server: Server | null, enabled: boolean = true) {
+  const isVisible = usePageVisibility();
   // Store previous metrics for CPU rate calculation
   const prevSnapshot = useRef<MetricsSnapshot | null>(null);
 
@@ -30,7 +32,7 @@ export function useMetrics(server: Server | null, enabled: boolean = true) {
     swrKey,
     fetcher,
     {
-      refreshInterval: 5000, // Poll every 5 seconds for metrics
+      refreshInterval: (() => { const interval = isVisible ? 5000 : 0; console.log('[useMetrics] refreshInterval:', interval, 'isVisible:', isVisible); return interval; })(),
       revalidateOnFocus: true,
       dedupingInterval: 2000,
     }
diff --git a/web-ui/src/lib/hooks/usePageVisibility.ts b/web-ui/src/lib/hooks/usePageVisibility.ts
new file mode 100644
index 0000000..0f22186
--- /dev/null
+++ b/web-ui/src/lib/hooks/usePageVisibility.ts
@@ -0,0 +1,32 @@
+'use client';
+
+import { useState, useEffect, useCallback } from 'react';
+
+/**
+ * Hook that tracks whether the browser tab/window is active.
+ * Returns false when:
+ * - The tab is hidden (user switched browser tabs)
+ * - The browser window lost focus (user switched to another application)
+ */
+export function usePageVisibility(): boolean {
+  const [isVisible, setIsVisible] = useState(true);
+
+  const update = useCallback(() => {
+    const visible = !document.hidden && document.hasFocus();
+    console.log('[usePageVisibility]', visible ? 'ACTIVE' : 'INACTIVE', '| hidden:', document.hidden, 'hasFocus:', document.hasFocus());
+    setIsVisible(visible);
+  }, []);
+
+  useEffect(() => {
+    document.addEventListener('visibilitychange', update);
+    window.addEventListener('focus', update);
+    window.addEventListener('blur', update);
+    return () => {
+      document.removeEventListener('visibilitychange', update);
+      window.removeEventListener('focus', update);
+      window.removeEventListener('blur', update);
+    };
+  }, [update]);
+
+  return isVisible;
+}
diff --git a/web-ui/src/lib/hooks/useSecurity.ts b/web-ui/src/lib/hooks/useSecurity.ts
index 3d830d3..f1be0a5 100644
--- a/web-ui/src/lib/hooks/useSecurity.ts
+++ b/web-ui/src/lib/hooks/useSecurity.ts
@@ -4,11 +4,13 @@ import useSWR from 'swr';
 import { Server } from '@/src/types/server';
 import { ClamavSummaryResponse } from '@/src/types/security';
 import { getClient } from '@/src/lib/api/client';
+import { usePageVisibility } from './usePageVisibility';
 
 /**
  * Hook for fetching ClamAV security summary
  */
 export function useSecurity(server: Server | null) {
+  const isVisible = usePageVisibility();
   const fetcher = async (): Promise<ClamavSummaryResponse> => {
     if (!server) throw new Error('No server');
     const client = getClient(server);
@@ -21,7 +23,7 @@ export function useSecurity(server: Server | null) {
     swrKey,
     fetcher,
     {
-      refreshInterval: 60000, // 60s refresh
+      refreshInterval: isVisible ? 60000 : 0, // 60s refresh (paused when tab hidden)
       revalidateOnFocus: true,
       dedupingInterval: 10000,
     }
diff --git a/web-ui/src/lib/hooks/useTraffic.ts b/web-ui/src/lib/hooks/useTraffic.ts
index b9c0ed5..e5722ae 100644
--- a/web-ui/src/lib/hooks/useTraffic.ts
+++ b/web-ui/src/lib/hooks/useTraffic.ts
@@ -7,11 +7,13 @@ import { Connection, ConnectionSummary, HistoricalConnection, TrafficAggregate }
 import { getClient } from '@/src/lib/api/client';
 import { useEventStream } from '@/src/lib/events/useEventStream';
 import { ServerEvent } from '@/src/types/events';
+import { usePageVisibility } from './usePageVisibility';
 
 /**
  * Hook for managing traffic monitoring for a specific container
  */
 export function useTraffic(server: Server | null, containerName: string | null) {
+  const isVisible = usePageVisibility();
   const [autoRefresh, setAutoRefresh] = useState(true);
 
   // Fetcher for active connections
@@ -31,7 +33,7 @@ export function useTraffic(server: Server | null, containerName: string | null)
     isLoading: connectionsLoading,
     mutate: mutateConnections,
   } = useSWR<Connection[]>(connectionsKey, connectionsFetcher, {
-    refreshInterval: autoRefresh ? 5000 : 0, // Poll every 5 seconds if auto-refresh enabled
+    refreshInterval: autoRefresh && isVisible ? 5000 : 0, // Poll every 5 seconds if auto-refresh enabled
     revalidateOnFocus: true,
     dedupingInterval: 2000,
   });
@@ -52,7 +54,7 @@ export function useTraffic(server: Server | null, containerName: string | null)
     isLoading: summaryLoading,
     mutate: mutateSummary,
   } = useSWR<ConnectionSummary | null>(summaryKey, summaryFetcher, {
-    refreshInterval: autoRefresh ? 5000 : 0,
+    refreshInterval: autoRefresh && isVisible ? 5000 : 0,
     revalidateOnFocus: true,
     dedupingInterval: 2000,
   });