diff --git a/webui/src/components/Sidebar.tsx b/webui/src/components/Sidebar.tsx
index 3d4f7a6d2..671ed701f 100644
--- a/webui/src/components/Sidebar.tsx
+++ b/webui/src/components/Sidebar.tsx
@@ -55,12 +55,29 @@ interface SidebarProps {
   hostChromeInset?: boolean;
 }
 
+type NavigatorWithUserAgentData = Navigator & {
+  userAgentData?: { platform?: string };
+};
+
+function isApplePlatform(): boolean {
+  if (typeof navigator === "undefined") return false;
+  const platform = navigator.platform || "";
+  const userAgentPlatform =
+    (navigator as NavigatorWithUserAgentData).userAgentData?.platform || "";
+  return /mac|iphone|ipad|ipod/i.test(`${platform} ${userAgentPlatform}`);
+}
+
+function newChatShortcutLabel(): string {
+  return isApplePlatform() ? "⌘⇧O" : "Ctrl+Shift+O";
+}
+
 export function Sidebar(props: SidebarProps) {
   const { t } = useTranslation();
   const [menuPortalContainer, setMenuPortalContainer] =
     useState<HTMLElement | null>(null);
   const collapsed = Boolean(props.collapsed);
   const toggleLabel = t("thread.header.toggleSidebar");
+  const newChatShortcut = newChatShortcutLabel();
 
   return (
     <nav
@@ -124,7 +141,8 @@ export function Sidebar(props: SidebarProps) {
           label={t("sidebar.newChat")}
           onClick={props.onNewChat}
           icon={<SquarePen className="h-4 w-4" />}
-          shortcut="Cmd/Ctrl+Shift+O"
+          shortcut={newChatShortcut}
+          ariaKeyShortcuts="Meta+Shift+O Control+Shift+O"
         />
         <SidebarActionButton
           collapsed={collapsed}
@@ -215,6 +233,7 @@ function SidebarActionButton({
   active = false,
   className,
   shortcut,
+  ariaKeyShortcuts,
 }: {
   collapsed: boolean;
   label: string;
@@ -223,6 +242,7 @@ function SidebarActionButton({
   active?: boolean;
   className?: string;
   shortcut?: string;
+  ariaKeyShortcuts?: string;
 }) {
   const title = shortcut ? `${label} (${shortcut})` : collapsed ? label : undefined;
 
@@ -232,6 +252,7 @@ function SidebarActionButton({
       variant="ghost"
       aria-label={label}
       aria-current={active ? "page" : undefined}
+      aria-keyshortcuts={ariaKeyShortcuts}
       title={title}
       onClick={() => onClick()}
       className={cn(
diff --git a/webui/src/tests/app-layout.test.tsx b/webui/src/tests/app-layout.test.tsx
index 98f5f7f9e..870f71e16 100644
--- a/webui/src/tests/app-layout.test.tsx
+++ b/webui/src/tests/app-layout.test.tsx
@@ -15,6 +15,13 @@ let mockSessions: ChatSummary[] = [];
 const HERO_GREETING_PATTERN =
   /What should we work on\?|Where should we start\?|What are we building today\?|What should we tackle together\?/;
 
+function setNavigatorPlatform(platform: string): void {
+  Object.defineProperty(window.navigator, "platform", {
+    configurable: true,
+    value: platform,
+  });
+}
+
 function jsonResponse(body: unknown): Response {
   return {
     ok: true,
@@ -200,6 +207,7 @@ describe("App layout", () => {
     attachSpy.mockReset();
     runStatusHandlers.clear();
     window.history.replaceState(null, "", "/");
+    setNavigatorPlatform("Linux x86_64");
     localStorage.removeItem("nanobot-webui.sidebar.completed-runs.v1");
     vi.mocked(fetchBootstrap).mockReset().mockResolvedValue({
       token: "tok",
@@ -1409,9 +1417,27 @@ describe("App layout", () => {
     await waitFor(() => expect(connectSpy).toHaveBeenCalled());
     const sidebar = screen.getByRole("navigation", { name: "Sidebar navigation" });
 
+    const newChatButton = within(sidebar).getByRole("button", { name: "New chat" });
+    expect(newChatButton).toHaveAttribute(
+      "title",
+      "New chat (Ctrl+Shift+O)",
+    );
+    expect(newChatButton).toHaveAttribute(
+      "aria-keyshortcuts",
+      "Meta+Shift+O Control+Shift+O",
+    );
+  });
+
+  it("uses macOS shortcut glyphs in the sidebar title", async () => {
+    setNavigatorPlatform("MacIntel");
+    render(<App />);
+
+    await waitFor(() => expect(connectSpy).toHaveBeenCalled());
+    const sidebar = screen.getByRole("navigation", { name: "Sidebar navigation" });
+
     expect(within(sidebar).getByRole("button", { name: "New chat" })).toHaveAttribute(
       "title",
-      "New chat (Cmd/Ctrl+Shift+O)",
+      "New chat (⌘⇧O)",
     );
   });