diff --git a/web/src/app/pattern-lab/HardwareModal.test.tsx b/web/src/app/pattern-lab/HardwareModal.test.tsx
index 6a86a56a0..eb4db6989 100644
--- a/web/src/app/pattern-lab/HardwareModal.test.tsx
+++ b/web/src/app/pattern-lab/HardwareModal.test.tsx
@@ -132,6 +132,29 @@ describe("HardwareModal", () => {
     expectHeaderKept();
   });
 
+  // The prompt goes to a model by paste. When the browser refuses the write,
+  // the label used to stay as it was, and the paste carried whatever the
+  // clipboard held before.
+  it("says Copy failed on the button whose copy the browser refused", async () => {
+    const writeText = vi.fn<(text: string) => Promise<void>>(() =>
+      Promise.reject(new DOMException("Write permission denied.", "NotAllowedError")),
+    );
+    Object.defineProperty(navigator, "clipboard", { configurable: true, value: { writeText } });
+    try {
+      render(<Lab />);
+      fireEvent.click(screen.getByText("Copy the conversion prompt"));
+      expect(await screen.findByText("Copy failed")).toBeTruthy();
+      expect(screen.getByText("Copy .h")).toBeTruthy();
+
+      writeText.mockImplementation(() => Promise.resolve());
+      fireEvent.click(screen.getByText("Copy failed"));
+      expect(await screen.findByText("Copied ✓")).toBeTruthy();
+      expect(writeText).toHaveBeenCalledTimes(2);
+    } finally {
+      delete (navigator as { clipboard?: unknown }).clipboard;
+    }
+  });
+
   it("Esc over the Publish modal closes Publish alone and keeps the header", async () => {
     render(<Lab />);
     pasteHeaderAndContinue();
diff --git a/web/src/app/pattern-lab/HardwareModal.tsx b/web/src/app/pattern-lab/HardwareModal.tsx
index d0b9a1732..dda5ada6a 100644
--- a/web/src/app/pattern-lab/HardwareModal.tsx
+++ b/web/src/app/pattern-lab/HardwareModal.tsx
@@ -49,7 +49,7 @@ export default function HardwareModal({
   const [name, setName] = useState(() => labPatternName(useLabStore.getState()));
   const [pastes, setPastes] = useState<Record<number, string>>({});
   const [single, setSingle] = useState("");
-  const [copiedKey, flashCopied] = useResettingState<string | null>(null, 1200);
+  const [copied, flashCopied] = useResettingState<{ key: string; ok: boolean } | null>(null, 1200);
   const [stage, setStage] = useState<Stage>("convert");
 
   const [sendOpen, setSendOpen] = useState(false);
@@ -110,12 +110,17 @@ export default function HardwareModal({
   const copyText = async (key: string, text: string) => {
     try {
       await navigator.clipboard.writeText(text);
-      flashCopied(key);
+      flashCopied({ key, ok: true });
     } catch {
-      /* clipboard may be blocked */
+      // The browser refused the write. Saying nothing left the label as it
+      // was, and whatever the clipboard held before went to the model.
+      flashCopied({ key, ok: false });
     }
   };
 
+  const copyLabel = (key: string, idle: string) =>
+    copied?.key === key ? (copied.ok ? "Copied ✓" : "Copy failed") : idle;
+
   const downloadH = () => {
     const blob = new Blob([assembled], { type: "text/plain" });
     const url = URL.createObjectURL(blob);
@@ -217,7 +222,7 @@ export default function HardwareModal({
                           type="button"
                           onClick={() => void copyText(`u${unit.index}`, unit.prompt)}
                         >
-                          {copiedKey === `u${unit.index}` ? "Copied ✓" : "Copy prompt"}
+                          {copyLabel(`u${unit.index}`, "Copy prompt")}
                         </button>
                       </div>
                       <textarea
@@ -237,7 +242,7 @@ export default function HardwareModal({
                 <>
                   <div className={styles.variantActions}>
                     <button type="button" onClick={() => void copyText("single", singlePrompt)}>
-                      {copiedKey === "single" ? "Copied ✓" : "Copy the conversion prompt"}
+                      {copyLabel("single", "Copy the conversion prompt")}
                     </button>
                   </div>
                   <textarea
@@ -260,7 +265,7 @@ export default function HardwareModal({
 
               <div className={styles.variantActions} style={{ marginTop: 10, flexWrap: "wrap" }}>
                 <button type="button" onClick={() => void copyText("h", assembled)}>
-                  {copiedKey === "h" ? "Copied ✓" : "Copy .h"}
+                  {copyLabel("h", "Copy .h")}
                 </button>
                 <button type="button" onClick={downloadH} disabled={!headerLooksReal}>
                   Download .h
diff --git a/web/src/app/pattern-lab/panels/CodePanel.test.tsx b/web/src/app/pattern-lab/panels/CodePanel.test.tsx
new file mode 100644
index 000000000..4dbfd7d0c
--- /dev/null
+++ b/web/src/app/pattern-lab/panels/CodePanel.test.tsx
@@ -0,0 +1,77 @@
+// "Copy prompt" in the Code panel. A browser can refuse the clipboard write
+// (no permission, a page served over plain http). The button used to keep its
+// label and leave an unhandled rejection behind, so the next paste into the
+// model carried whatever the clipboard held before.
+
+import { act, fireEvent, render, screen } from "@testing-library/react";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import CodePanel from "./CodePanel";
+import { useLabStore } from "@/lib/lab/store";
+
+vi.mock("@monaco-editor/react", () => ({ default: () => <textarea aria-label="Code" /> }));
+
+function setClipboard(value: unknown) {
+  Object.defineProperty(navigator, "clipboard", { configurable: true, value });
+}
+
+beforeEach(() => {
+  useLabStore.getState().discardProject();
+});
+
+afterEach(() => {
+  delete (navigator as { clipboard?: unknown }).clipboard;
+});
+
+describe("CodePanel copy prompt", () => {
+  it("says Copied once the prompt is on the clipboard", async () => {
+    const writeText = vi.fn<(text: string) => Promise<void>>(() => Promise.resolve());
+    setClipboard({ writeText });
+    render(<CodePanel />);
+
+    fireEvent.click(screen.getByText("Copy prompt"));
+    await act(async () => {});
+
+    expect(writeText).toHaveBeenCalledTimes(1);
+    expect(screen.getByText("Copied")).toBeTruthy();
+  });
+
+  it("says Copy failed when the browser refuses the write", async () => {
+    const writeText = vi.fn<(text: string) => Promise<void>>(() =>
+      Promise.reject(new DOMException("Write permission denied.", "NotAllowedError")),
+    );
+    setClipboard({ writeText });
+    render(<CodePanel />);
+
+    fireEvent.click(screen.getByText("Copy prompt"));
+    await act(async () => {});
+
+    expect(screen.getByText("Copy failed")).toBeTruthy();
+    expect(screen.queryByText("Copied")).toBeNull();
+  });
+
+  it("says Copy failed on a page with no clipboard at all", async () => {
+    render(<CodePanel />);
+
+    fireEvent.click(screen.getByText("Copy prompt"));
+    await act(async () => {});
+
+    expect(screen.getByText("Copy failed")).toBeTruthy();
+  });
+
+  it("goes back to Copy prompt after a moment", async () => {
+    vi.useFakeTimers({ toFake: ["setTimeout", "clearTimeout"] });
+    try {
+      setClipboard({ writeText: () => Promise.reject(new Error("denied")) });
+      render(<CodePanel />);
+
+      fireEvent.click(screen.getByText("Copy prompt"));
+      await act(async () => {});
+      expect(screen.getByText("Copy failed")).toBeTruthy();
+
+      act(() => vi.advanceTimersByTime(1200));
+      expect(screen.getByText("Copy prompt")).toBeTruthy();
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+});
diff --git a/web/src/app/pattern-lab/panels/CodePanel.tsx b/web/src/app/pattern-lab/panels/CodePanel.tsx
index b00b282e3..0c7f4d9d6 100644
--- a/web/src/app/pattern-lab/panels/CodePanel.tsx
+++ b/web/src/app/pattern-lab/panels/CodePanel.tsx
@@ -32,7 +32,7 @@ export default function CodePanel() {
     layer ? (state.layerErrors[layer.id] ?? null) : null,
   );
 
-  const [promptCopied, setPromptCopied] = useResettingState(false, 1200);
+  const [promptCopy, flashPromptCopy] = useResettingState<"idle" | "copied" | "failed">("idle", 1200);
   const [pasted, setPasted] = useResettingState(false, 1200);
   const [cleared, setCleared] = useResettingState(false, 1200);
   const [guideOpen, setGuideOpen] = useState(false);
@@ -61,11 +61,17 @@ export default function CodePanel() {
     applyCodeToActive(labPresets[next].code);
   };
 
+  // A browser can refuse the write (no permission, a page served over plain
+  // http). The button says so, the way Pixel's "Copy as code" does.
   const copyVariantPrompt = async () => {
-    await navigator.clipboard.writeText(
-      buildVariantCopyPrompt(layer.code, knobs, ranges, gen.colorMode, matrix),
-    );
-    setPromptCopied(true);
+    try {
+      await navigator.clipboard.writeText(
+        buildVariantCopyPrompt(layer.code, knobs, ranges, gen.colorMode, matrix),
+      );
+      flashPromptCopy("copied");
+    } catch {
+      flashPromptCopy("failed");
+    }
   };
 
   // Pasted code carrying a @stack line is a whole shared composition —
@@ -139,7 +145,7 @@ export default function CodePanel() {
           onClick={copyVariantPrompt}
           title="Copy the AI variation prompt for this layer (ChatGPT / Claude / Gemini)"
         >
-          {promptCopied ? "Copied" : "Copy prompt"}
+          {promptCopy === "copied" ? "Copied" : promptCopy === "failed" ? "Copy failed" : "Copy prompt"}
         </button>
         <button type="button" onClick={() => setGuideOpen(true)}>
           Code guide
diff --git a/web/src/components/sections/PatternPanel.test.tsx b/web/src/components/sections/PatternPanel.test.tsx
index 81a109bcd..2223eb7e0 100644
--- a/web/src/components/sections/PatternPanel.test.tsx
+++ b/web/src/components/sections/PatternPanel.test.tsx
@@ -74,10 +74,11 @@ describe('PatternPanel', () => {
     expect(editor).toHaveAttribute('data-height', '100%');
   });
 
-  it('copies a creation prompt with the code in the editor and the step one detent moves Knob 2', () => {
+  it('copies a creation prompt with the code in the editor and the step one detent moves Knob 2', async () => {
     const writeText = vi.fn<(text: string) => Promise<void>>(() => Promise.resolve());
     Object.defineProperty(navigator, 'clipboard', { value: { writeText }, configurable: true });
-    vi.stubGlobal('alert', vi.fn());
+    const alert = vi.fn();
+    vi.stubGlobal('alert', alert);
     try {
       render(<PatternPanel content={content} isActive />);
       act(() => useAppStore.getState().setCustomJsCode('export function draw(display) {}'));
@@ -86,11 +87,53 @@ describe('PatternPanel', () => {
       const prompt = writeText.mock.calls[0]?.[0] ?? '';
       expect(prompt).toContain('- Knob 2: 0.1 to 10.0, clamps at edges, step 0.206 per detent.');
       expect(prompt).toContain('```javascript\nexport function draw(display) {}\n```');
+      await act(async () => {});
+      expect(alert).toHaveBeenCalledTimes(1);
+      expect(alert.mock.calls[0]?.[0]).toMatch(/^Creation prompt copied to clipboard!/);
     } finally {
       delete (navigator as { clipboard?: unknown }).clipboard;
     }
   });
 
+  // The alert used to go up before the write had finished, so a browser that
+  // refused it still said the prompt was copied.
+  it('says Copy failed instead of copied when the browser refuses the write', async () => {
+    const writeText = vi.fn<(text: string) => Promise<void>>(() =>
+      Promise.reject(new DOMException('Write permission denied.', 'NotAllowedError')),
+    );
+    Object.defineProperty(navigator, 'clipboard', { value: { writeText }, configurable: true });
+    const alert = vi.fn();
+    vi.stubGlobal('alert', alert);
+    try {
+      render(<PatternPanel content={content} isActive />);
+      screen.getByRole('button', { name: 'Copy creation prompt' }).click();
+      await act(async () => {});
+
+      expect(alert).not.toHaveBeenCalled();
+      expect(screen.getByRole('button', { name: 'Copy failed' })).toBeInTheDocument();
+    } finally {
+      delete (navigator as { clipboard?: unknown }).clipboard;
+    }
+  });
+
+  it('says Copy failed on a page with no clipboard at all, and comes back to its label', async () => {
+    vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout'] });
+    const alert = vi.fn();
+    vi.stubGlobal('alert', alert);
+    try {
+      render(<PatternPanel content={content} isActive />);
+      screen.getByRole('button', { name: 'Copy creation prompt' }).click();
+      await act(async () => {});
+
+      expect(alert).not.toHaveBeenCalled();
+      expect(screen.getByRole('button', { name: 'Copy failed' })).toBeInTheDocument();
+      act(() => vi.advanceTimersByTime(1400));
+      expect(screen.getByRole('button', { name: 'Copy creation prompt' })).toBeInTheDocument();
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
   // The build server bakes a .pfm on its own machine; nothing compiles in the
   // browser. Firmware is a PlatformIO build, which the firmware README puts
   // first.
diff --git a/web/src/components/sections/PatternPanel.tsx b/web/src/components/sections/PatternPanel.tsx
index fd03758af..e62baf492 100644
--- a/web/src/components/sections/PatternPanel.tsx
+++ b/web/src/components/sections/PatternPanel.tsx
@@ -10,6 +10,7 @@ import { showcasePresets } from '@/lib/presets';
 import { captureEvent } from '@/lib/posthogEvents';
 import { communityHref } from '@/lib/community/apiBase';
 import { useMediaQuery } from '@/lib/hooks/useMediaQuery';
+import { useResettingState } from '@/lib/hooks/useResettingState';
 import styles from './PatternPanel.module.css';
 import { getVariantPrompt } from './variantPrompt';
 
@@ -131,11 +132,21 @@ export default function PatternPanel({ content, isActive }: PatternPanelProps) {
   const [showAllPresets, setShowAllPresets] = useState(false);
   const activePreset = activePresetIndex >= 0 ? showcasePresets[activePresetIndex] : null;
 
-  const handleCopyVariantPrompt = () => {
-    navigator.clipboard.writeText(getVariantPrompt(customJsCode));
-    captureEvent('copy_variants_prompt_clicked', {
-      surface: 'live_editor',
-    });
+  // The alert says the prompt is on the clipboard, so it waits for the write.
+  // When the browser refuses it (no permission, a page served over plain
+  // http), the button says "Copy failed" for a moment instead.
+  const [copyFailed, flashCopyFailed] = useResettingState(false, 1400);
+  const handleCopyVariantPrompt = async () => {
+    try {
+      const copying = navigator.clipboard.writeText(getVariantPrompt(customJsCode));
+      captureEvent('copy_variants_prompt_clicked', {
+        surface: 'live_editor',
+      });
+      await copying;
+    } catch {
+      flashCopyFailed(true);
+      return;
+    }
     alert('Creation prompt copied to clipboard! Paste it in ChatGPT/Claude to get 5 pattern variations.');
   };
 
@@ -279,8 +290,8 @@ export default function PatternPanel({ content, isActive }: PatternPanelProps) {
                   Paste AI-generated code here, or edit the preset. The preview updates as
                   you type.
                 </span>
-                <button type="button" onClick={handleCopyVariantPrompt}>
-                  Copy creation prompt
+                <button type="button" onClick={() => void handleCopyVariantPrompt()}>
+                  {copyFailed ? 'Copy failed' : 'Copy creation prompt'}
                 </button>
               </div>
           </div>