diff --git a/ui/web/src/pages/pending-messages/pending-messages-page.tsx b/ui/web/src/pages/pending-messages/pending-messages-page.tsx
index ff1abe2a..fce8ff1e 100644
--- a/ui/web/src/pages/pending-messages/pending-messages-page.tsx
+++ b/ui/web/src/pages/pending-messages/pending-messages-page.tsx
@@ -1,4 +1,4 @@
-import { useState, useEffect } from "react";
+import { useState, useEffect, useRef } from "react";
 import { useTranslation } from "react-i18next";
 import { Inbox, RefreshCw, Trash2, Archive, Loader2, Info, ChevronDown, ChevronUp } from "lucide-react";
 import { Button } from "@/components/ui/button";
@@ -33,11 +33,30 @@ export function PendingMessagesPage() {
   const [confirmClear, setConfirmClear] = useState<PendingMessageGroup | null>(null);
   const [actionLoading, setActionLoading] = useState<string | null>(null);
   const [compactingKey, setCompactingKey] = useState<string | null>(null);
+  const pollRef = useRef<ReturnType<typeof setInterval> | null>(null);
+  const timeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
 
   useEffect(() => {
     loadGroups();
   }, [loadGroups]);
 
+  // Clear spinner as soon as the compacting group's has_summary becomes true
+  useEffect(() => {
+    if (!compactingKey) return;
+    const [channel, historyKey] = compactingKey.split("/");
+    const group = groups.find(
+      (g) => g.channel_name === channel && g.history_key === historyKey,
+    );
+    if (group?.has_summary) {
+      if (pollRef.current) clearInterval(pollRef.current);
+      if (timeoutRef.current) clearTimeout(timeoutRef.current);
+      pollRef.current = null;
+      timeoutRef.current = null;
+      setCompactingKey(null);
+      setActionLoading(null);
+    }
+  }, [groups, compactingKey]);
+
   const handleRefresh = () => loadGroups();
 
   const handleCompact = async (e: React.MouseEvent, group: PendingMessageGroup) => {
@@ -52,10 +71,16 @@ export function PendingMessagesPage() {
       return;
     }
     // Backend runs LLM in background — poll until done (has_summary changes).
-    // Compact button is already disabled when has_summary=true.
-    const poll = setInterval(() => loadGroups(), 5000);
+    // useEffect above clears spinner when has_summary becomes true.
+    pollRef.current = setInterval(() => loadGroups(), 5000);
     setTimeout(() => loadGroups(), 2000); // quick first check
-    setTimeout(() => { clearInterval(poll); setCompactingKey(null); setActionLoading(null); }, 120_000);
+    timeoutRef.current = setTimeout(() => {
+      if (pollRef.current) clearInterval(pollRef.current);
+      pollRef.current = null;
+      timeoutRef.current = null;
+      setCompactingKey(null);
+      setActionLoading(null);
+    }, 120_000);
   };
 
   const handleClear = async (group: PendingMessageGroup) => {