diff --git a/apps/web/components/task/preview-session-tabs.tsx b/apps/web/components/task/preview-session-tabs.tsx
index d3c2642547..25845d19a7 100644
--- a/apps/web/components/task/preview-session-tabs.tsx
+++ b/apps/web/components/task/preview-session-tabs.tsx
@@ -4,6 +4,7 @@ import { useCallback, useMemo } from "react";
 import { IconLoader2 } from "@tabler/icons-react";
 import { Button } from "@kandev/ui/button";
 import { AgentLogo } from "@/components/agent-logo";
+import { GridSpinner } from "@/components/grid-spinner";
 import { SessionTabs, type SessionTab } from "@/components/session-tabs";
 import { useAppStore } from "@/components/state-provider";
 import { useToast } from "@/components/toast-provider";
@@ -11,12 +12,13 @@ import { useSessionResumption } from "@/hooks/domains/session/use-session-resump
 import { useTaskSessions } from "@/hooks/use-task-sessions";
 import type { UseEnsureTaskSessionResult } from "@/hooks/domains/session/use-ensure-task-session";
 import type { AgentProfileOption } from "@/lib/state/slices";
-import type { TaskSession, TaskSessionState } from "@/lib/types/http";
+import type { TaskSession } from "@/lib/types/http";
 import { getWebSocketClient } from "@/lib/ws/connection";
 import { PassthroughTerminal } from "./passthrough-terminal";
 import { TaskChatPanel } from "./task-chat-panel";
 import {
   buildAgentLabelsById,
+  isSessionActive,
   pickActiveSessionId,
   resolveAgentLabelFor,
   sortSessions,
@@ -174,12 +176,8 @@ function PreviewSessionBody({ session, taskId }: { session: TaskSession; taskId:
   );
 }
 
-function isSessionActive(state: TaskSessionState): boolean {
-  return state === "RUNNING" || state === "STARTING";
-}
-
 function RunningSpinner() {
-  return <IconLoader2 className="h-3 w-3 shrink-0 text-blue-500 animate-spin" />;
+  return <GridSpinner className="text-muted-foreground shrink-0 text-[12px]" />;
 }
 
 function PreviewLoadingState({ label }: { label: string }) {
diff --git a/apps/web/components/task/session-sort.test.ts b/apps/web/components/task/session-sort.test.ts
index c6e9399770..f48cff5bfa 100644
--- a/apps/web/components/task/session-sort.test.ts
+++ b/apps/web/components/task/session-sort.test.ts
@@ -1,6 +1,7 @@
 import { describe, expect, it } from "vitest";
 import {
   buildAgentLabelsById,
+  isSessionActive,
   pickActiveSessionId,
   resolveAgentLabelFor,
   sortSessions,
@@ -83,3 +84,23 @@ describe("pickActiveSessionId", () => {
     expect(pickActiveSessionId(sessions, null)).toBe("a");
   });
 });
+
+describe("isSessionActive", () => {
+  it("is true while the agent is starting or running", () => {
+    expect(isSessionActive("RUNNING")).toBe(true);
+    expect(isSessionActive("STARTING")).toBe(true);
+  });
+
+  it("is false for terminal and idle states", () => {
+    expect(isSessionActive("WAITING_FOR_INPUT")).toBe(false);
+    expect(isSessionActive("COMPLETED")).toBe(false);
+    expect(isSessionActive("FAILED")).toBe(false);
+    expect(isSessionActive("CANCELLED")).toBe(false);
+    expect(isSessionActive("CREATED")).toBe(false);
+  });
+
+  it("is false for null/undefined", () => {
+    expect(isSessionActive(null)).toBe(false);
+    expect(isSessionActive(undefined)).toBe(false);
+  });
+});
diff --git a/apps/web/components/task/session-sort.ts b/apps/web/components/task/session-sort.ts
index a5b3e8fb14..4d91df0921 100644
--- a/apps/web/components/task/session-sort.ts
+++ b/apps/web/components/task/session-sort.ts
@@ -57,3 +57,7 @@ export function pickActiveSessionId(
   const primary = sessions.find((s) => s.is_primary);
   return (primary ?? sessions[0]).id;
 }
+
+export function isSessionActive(state: TaskSessionState | null | undefined): boolean {
+  return state === "RUNNING" || state === "STARTING";
+}
diff --git a/apps/web/components/task/session-tab.tsx b/apps/web/components/task/session-tab.tsx
index 0412d78606..4ca533c583 100644
--- a/apps/web/components/task/session-tab.tsx
+++ b/apps/web/components/task/session-tab.tsx
@@ -4,6 +4,7 @@ import { useCallback, useEffect, useState } from "react";
 import { DockviewDefaultTab, type IDockviewPanelHeaderProps } from "dockview-react";
 import { IconStar } from "@tabler/icons-react";
 import { AgentLogo } from "@/components/agent-logo";
+import { GridSpinner } from "@/components/grid-spinner";
 import {
   ContextMenu,
   ContextMenuContent,
@@ -29,6 +30,7 @@ import {
   isSessionResumable as isResumable,
 } from "@/hooks/domains/session/use-session-actions";
 import type { TaskSessionState } from "@/lib/types/http";
+import { isSessionActive } from "./session-sort";
 import { useTabMaximizeOnDoubleClick } from "./use-tab-maximize";
 
 function useSessionTabState(sessionId: string | undefined) {
@@ -244,13 +246,18 @@ export function SessionTab(props: IDockviewPanelHeaderProps) {
                 {sessionNumber}
               </span>
             )}
-            {agentName && (
-              <AgentLogo
-                agentName={agentName}
-                size={14}
-                className={`ml-1.5 shrink-0${isActive ? "" : " opacity-50"}`}
-              />
-            )}
+            {agentName &&
+              (isSessionActive(sessionState) ? (
+                <GridSpinner
+                  className={`ml-1.5 shrink-0 text-[14px] text-muted-foreground${isActive ? "" : " opacity-50"}`}
+                />
+              ) : (
+                <AgentLogo
+                  agentName={agentName}
+                  size={14}
+                  className={`ml-1.5 shrink-0${isActive ? "" : " opacity-50"}`}
+                />
+              ))}
             <DockviewDefaultTab {...props} hideClose={sessionCount <= 1} />
           </div>
         </ContextMenuTrigger>