diff --git a/apps/web/src/components/chat/ComposerPrimaryActions.test.ts b/apps/web/src/components/chat/ComposerPrimaryActions.test.ts
index b7624db0a8f..ba416e9fce3 100644
--- a/apps/web/src/components/chat/ComposerPrimaryActions.test.ts
+++ b/apps/web/src/components/chat/ComposerPrimaryActions.test.ts
@@ -1,6 +1,64 @@
-import { describe, expect, it } from "vite-plus/test";
+import { createElement } from "react";
+import { renderToStaticMarkup } from "react-dom/server";
+import { describe, expect, it, vi } from "vite-plus/test";
 
-import { formatPendingPrimaryActionLabel } from "./ComposerPrimaryActions";
+vi.mock("~/hooks/useSettings", () => ({
+  useEnvironmentIdentificationMode: () => "none",
+}));
+vi.mock("../SidebarStageBackdrop", () => ({
+  StageBackdropButtonArt: () => null,
+  useSidebarStageBackdropVariant: () => null,
+}));
+
+import { ComposerPrimaryActions, formatPendingPrimaryActionLabel } from "./ComposerPrimaryActions";
+
+function renderPendingActions(isRunning: boolean) {
+  return renderToStaticMarkup(
+    createElement(ComposerPrimaryActions, {
+      compact: true,
+      pendingAction: {
+        questionIndex: 0,
+        isLastQuestion: true,
+        canAdvance: true,
+        isResponding: false,
+        isComplete: true,
+      },
+      isRunning,
+      showPlanFollowUpPrompt: false,
+      promptHasText: false,
+      isSendBusy: false,
+      sendDisabledReason: null,
+      isConnecting: false,
+      isEnvironmentUnavailable: false,
+      isPreparingWorktree: false,
+      hasSendableContent: false,
+      onPreviousPendingQuestion: () => {},
+      onInterrupt: () => {},
+      onImplementPlanInNewThread: () => {},
+    }),
+  );
+}
+
+function renderStandaloneStop() {
+  return renderToStaticMarkup(
+    createElement(ComposerPrimaryActions, {
+      compact: true,
+      pendingAction: null,
+      isRunning: true,
+      showPlanFollowUpPrompt: false,
+      promptHasText: false,
+      isSendBusy: false,
+      sendDisabledReason: null,
+      isConnecting: false,
+      isEnvironmentUnavailable: false,
+      isPreparingWorktree: false,
+      hasSendableContent: false,
+      onPreviousPendingQuestion: () => {},
+      onInterrupt: () => {},
+      onImplementPlanInNewThread: () => {},
+    }),
+  );
+}
 
 describe("formatPendingPrimaryActionLabel", () => {
   it("returns 'Submitting...' while responding", () => {
@@ -91,3 +149,19 @@ describe("formatPendingPrimaryActionLabel", () => {
     ).toBe("Submit answers");
   });
 });
+
+describe("ComposerPrimaryActions", () => {
+  it("offers Stop generation while a running turn is waiting for user input", () => {
+    expect(renderPendingActions(true)).toContain('aria-label="Stop generation"');
+  });
+
+  it("does not offer Stop generation for a pending request without a running turn", () => {
+    expect(renderPendingActions(false)).not.toContain('aria-label="Stop generation"');
+  });
+
+  it("matches the small pending action size without changing the standalone size", () => {
+    expect(renderPendingActions(true)).toContain("size-8 sm:size-7");
+    expect(renderStandaloneStop()).toContain("size-8 sm:h-8 sm:w-8");
+    expect(renderStandaloneStop()).not.toContain("sm:size-7");
+  });
+});
diff --git a/apps/web/src/components/chat/ComposerPrimaryActions.tsx b/apps/web/src/components/chat/ComposerPrimaryActions.tsx
index 504b7e1cc44..516d9267090 100644
--- a/apps/web/src/components/chat/ComposerPrimaryActions.tsx
+++ b/apps/web/src/components/chat/ComposerPrimaryActions.tsx
@@ -80,10 +80,27 @@ export const ComposerPrimaryActions = memo(function ComposerPrimaryActions({
   const stageBackdropVariant = useSidebarStageBackdropVariant(
     environmentIdentificationMode === "artwork",
   );
+  const renderStopGenerationButton = (insidePendingAction: boolean) => (
+    <button
+      type="button"
+      className={cn(
+        "flex cursor-pointer items-center justify-center rounded-full bg-destructive/90 text-white shadow-xs shadow-destructive/24 inset-shadow-[0_1px_--theme(--color-white/16%)] transition-all duration-150 hover:bg-destructive hover:scale-105 active:inset-shadow-[0_1px_--theme(--color-black/8%)] active:shadow-none",
+        insidePendingAction ? "size-8 sm:size-7" : "size-8 sm:h-8 sm:w-8",
+      )}
+      {...pointerFocusProps}
+      onClick={onInterrupt}
+      aria-label="Stop generation"
+    >
+      <svg width="12" height="12" viewBox="0 0 12 12" fill="currentColor" aria-hidden="true">
+        <rect x="2" y="2" width="8" height="8" rx="1.5" />
+      </svg>
+    </button>
+  );
 
   if (pendingAction) {
     return (
       <div className={cn("flex items-center justify-end", compact ? "gap-1.5" : "gap-2")}>
+        {isRunning ? renderStopGenerationButton(true) : null}
         {pendingAction.questionIndex > 0 ? (
           compact ? (
             <Button
@@ -133,19 +150,7 @@ export const ComposerPrimaryActions = memo(function ComposerPrimaryActions({
   }
 
   if (isRunning) {
-    return (
-      <button
-        type="button"
-        className="flex size-8 cursor-pointer items-center justify-center rounded-full bg-destructive/90 text-white shadow-xs shadow-destructive/24 inset-shadow-[0_1px_--theme(--color-white/16%)] transition-all duration-150 hover:bg-destructive hover:scale-105 active:inset-shadow-[0_1px_--theme(--color-black/8%)] active:shadow-none sm:h-8 sm:w-8"
-        {...pointerFocusProps}
-        onClick={onInterrupt}
-        aria-label="Stop generation"
-      >
-        <svg width="12" height="12" viewBox="0 0 12 12" fill="currentColor" aria-hidden="true">
-          <rect x="2" y="2" width="8" height="8" rx="1.5" />
-        </svg>
-      </button>
-    );
+    return renderStopGenerationButton(false);
   }
 
   if (showPlanFollowUpPrompt) {