diff --git a/ui/src/app/api-keys/page.tsx b/ui/src/app/api-keys/page.tsx
index eb3c2955..fd384e95 100644
--- a/ui/src/app/api-keys/page.tsx
+++ b/ui/src/app/api-keys/page.tsx
@@ -2,6 +2,7 @@
 
 import { Copy, Eye, EyeOff, Key, Plus, RefreshCw, Trash2 } from 'lucide-react';
 import { useCallback, useEffect, useState } from 'react';
+import { toast } from 'sonner';
 
 import {
     archiveApiKeyApiV1UserApiKeysApiKeyIdDelete,
@@ -23,6 +24,7 @@ import { Skeleton } from '@/components/ui/skeleton';
 import { useAppConfig } from '@/context/AppConfigContext';
 import { useOrganizationTimezone } from '@/hooks/useOrganizationTimezone';
 import { useAuth } from '@/lib/auth';
+import { copyTextToClipboard } from '@/lib/clipboard';
 import { formatDateTime } from '@/lib/dateTime';
 import logger from '@/lib/logger';
 
@@ -287,9 +289,11 @@ export default function APIKeysPage() {
 
     const copyToClipboard = async (text: string) => {
         try {
-            await navigator.clipboard.writeText(text);
+            await copyTextToClipboard(text);
+            toast.success('Key copied to clipboard');
         } catch (err) {
             console.error('Failed to copy to clipboard:', err);
+            toast.error('Failed to copy key');
         }
     };
 
diff --git a/ui/src/lib/clipboard.test.ts b/ui/src/lib/clipboard.test.ts
new file mode 100644
index 00000000..08e5c9bc
--- /dev/null
+++ b/ui/src/lib/clipboard.test.ts
@@ -0,0 +1,76 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+import { copyTextToClipboard } from "./clipboard";
+
+const originalExecCommand = document.execCommand;
+
+describe("copyTextToClipboard", () => {
+    afterEach(() => {
+        vi.unstubAllGlobals();
+        vi.restoreAllMocks();
+
+        Object.defineProperty(document, "execCommand", {
+            configurable: true,
+            value: originalExecCommand,
+        });
+        document.querySelectorAll("textarea").forEach((element) => element.remove());
+    });
+
+    it("uses the Clipboard API when it is available", async () => {
+        const writeText = vi.fn().mockResolvedValue(undefined);
+        const execCommand = vi.fn();
+        vi.stubGlobal("navigator", { clipboard: { writeText } });
+        Object.defineProperty(document, "execCommand", {
+            configurable: true,
+            value: execCommand,
+        });
+
+        await copyTextToClipboard("secret");
+
+        expect(writeText).toHaveBeenCalledWith("secret");
+        expect(execCommand).not.toHaveBeenCalled();
+    });
+
+    it("uses the DOM fallback when the Clipboard API is unavailable", async () => {
+        const execCommand = vi.fn().mockReturnValue(true);
+        vi.stubGlobal("navigator", {});
+        Object.defineProperty(document, "execCommand", {
+            configurable: true,
+            value: execCommand,
+        });
+
+        await copyTextToClipboard("secret");
+
+        expect(execCommand).toHaveBeenCalledWith("copy");
+        expect(document.querySelector("textarea")).toBeNull();
+    });
+
+    it("uses the DOM fallback when Clipboard API access is denied", async () => {
+        const writeText = vi.fn().mockRejectedValue(new Error("denied"));
+        const execCommand = vi.fn().mockReturnValue(true);
+        vi.stubGlobal("navigator", { clipboard: { writeText } });
+        Object.defineProperty(document, "execCommand", {
+            configurable: true,
+            value: execCommand,
+        });
+
+        await copyTextToClipboard("secret");
+
+        expect(writeText).toHaveBeenCalledWith("secret");
+        expect(execCommand).toHaveBeenCalledWith("copy");
+    });
+
+    it("rejects and removes the temporary element when copying fails", async () => {
+        const execCommand = vi.fn().mockReturnValue(false);
+        vi.stubGlobal("navigator", {});
+        Object.defineProperty(document, "execCommand", {
+            configurable: true,
+            value: execCommand,
+        });
+
+        await expect(copyTextToClipboard("secret")).rejects.toThrow(
+            "Copy command was unsuccessful",
+        );
+        expect(document.querySelector("textarea")).toBeNull();
+    });
+});
diff --git a/ui/src/lib/clipboard.ts b/ui/src/lib/clipboard.ts
new file mode 100644
index 00000000..dae92fff
--- /dev/null
+++ b/ui/src/lib/clipboard.ts
@@ -0,0 +1,33 @@
+export async function copyTextToClipboard(text: string): Promise<void> {
+    if (typeof navigator !== "undefined" && navigator.clipboard?.writeText) {
+        try {
+            await navigator.clipboard.writeText(text);
+            return;
+        } catch {
+            // Fall back to the legacy copy command when Clipboard API access is denied.
+        }
+    }
+
+    if (typeof document === "undefined" || typeof document.execCommand !== "function") {
+        throw new Error("Clipboard access is unavailable");
+    }
+
+    const textArea = document.createElement("textarea");
+    textArea.value = text;
+    textArea.setAttribute("readonly", "");
+    textArea.style.position = "fixed";
+    textArea.style.opacity = "0";
+    textArea.style.pointerEvents = "none";
+    document.body.appendChild(textArea);
+
+    try {
+        textArea.select();
+        textArea.setSelectionRange(0, text.length);
+
+        if (!document.execCommand("copy")) {
+            throw new Error("Copy command was unsuccessful");
+        }
+    } finally {
+        textArea.remove();
+    }
+}