diff --git a/src/lib/nezha-api.ts b/src/lib/nezha-api.ts
index 175d1ce..32a1546 100644
--- a/src/lib/nezha-api.ts
+++ b/src/lib/nezha-api.ts
@@ -9,6 +9,14 @@ import type {
 	SettingResponse,
 } from "@/types/nezha-api";
 
+export const API_ERROR_UNAUTHORIZED = "ApiErrorUnauthorized";
+
+export function isUnauthorizedError(error: unknown): boolean {
+	const message =
+		error instanceof Error ? error.message : error == null ? "" : String(error);
+	return message === API_ERROR_UNAUTHORIZED;
+}
+
 let lastestRefreshTokenAt = 0;
 
 const getCookieValue = (name: string): string | undefined => {
diff --git a/src/locales/en/translation.json b/src/locales/en/translation.json
index 6cdbd61..0b6a474 100644
--- a/src/locales/en/translation.json
+++ b/src/locales/en/translation.json
@@ -115,7 +115,9 @@
 		"pageNotFound": "Page not found",
 		"backToHome": "Back to home",
 		"backendUnavailableTitle": "Backend API unavailable",
-		"backendUnavailableDescription": "The page is still available, but data cannot be loaded right now."
+		"backendUnavailableDescription": "The page is still available, but data cannot be loaded right now.",
+		"loginRequiredTitle": "Login required",
+		"loginRequiredDescription": "This site requires a login to load monitoring data."
 	},
 	"tabSwitch": {
 		"Detail": "Detail",
diff --git a/src/locales/id/translation.json b/src/locales/id/translation.json
index c7cfda6..7cb3e74 100644
--- a/src/locales/id/translation.json
+++ b/src/locales/id/translation.json
@@ -108,7 +108,9 @@
 		"pageNotFound": "Halaman tidak ditemukan",
 		"backToHome": "Kembali ke beranda",
 		"backendUnavailableTitle": "API backend tidak tersedia",
-		"backendUnavailableDescription": "Halaman masih tersedia, tetapi data tidak dapat dimuat saat ini."
+		"backendUnavailableDescription": "Halaman masih tersedia, tetapi data tidak dapat dimuat saat ini.",
+		"loginRequiredTitle": "Perlu masuk",
+		"loginRequiredDescription": "Situs ini memerlukan login untuk memuat data pemantauan."
 	},
 	"tabSwitch": {
 		"Detail": "Detail",
diff --git a/src/locales/pt_BR/translation.json b/src/locales/pt_BR/translation.json
index 9368fd5..745af41 100644
--- a/src/locales/pt_BR/translation.json
+++ b/src/locales/pt_BR/translation.json
@@ -108,7 +108,9 @@
 		"pageNotFound": "Página não encontrada",
 		"backToHome": "Voltar ao inicio",
 		"backendUnavailableTitle": "API Backend indisponível",
-		"backendUnavailableDescription": "A página ainda está disponível, mas os dados não podem ser carregados agora."
+		"backendUnavailableDescription": "A página ainda está disponível, mas os dados não podem ser carregados agora.",
+		"loginRequiredTitle": "Login necessário",
+		"loginRequiredDescription": "Este site exige login para carregar os dados de monitoramento."
 	},
 	"tabSwitch": {
 		"Detail": "Detalhes",
diff --git a/src/locales/zh-CN/translation.json b/src/locales/zh-CN/translation.json
index 04b967a..bc421ce 100644
--- a/src/locales/zh-CN/translation.json
+++ b/src/locales/zh-CN/translation.json
@@ -109,7 +109,9 @@
 		"pageNotFound": "页面不存在",
 		"backToHome": "回到主页",
 		"backendUnavailableTitle": "后端 API 无法访问",
-		"backendUnavailableDescription": "页面仍会正常显示，但暂时无法加载监控数据。"
+		"backendUnavailableDescription": "页面仍会正常显示，但暂时无法加载监控数据。",
+		"loginRequiredTitle": "需要登录",
+		"loginRequiredDescription": "当前站点已开启强制登录，登录后即可加载监控数据。"
 	},
 	"tabSwitch": {
 		"Detail": "详情",
diff --git a/src/pages/Server.tsx b/src/pages/Server.tsx
index 20cc1a9..dcca4bf 100644
--- a/src/pages/Server.tsx
+++ b/src/pages/Server.tsx
@@ -17,11 +17,16 @@ import ServerCard from "@/components/ServerCard";
 import ServerCardInline from "@/components/ServerCardInline";
 import ServerOverview from "@/components/ServerOverview";
 import { ServiceTracker } from "@/components/ServiceTracker";
+import { Button } from "@/components/ui/button";
 import { SORT_TYPES } from "@/context/sort-context";
 import { useSort } from "@/hooks/use-sort";
 import { useStatus } from "@/hooks/use-status";
 import { useWebSocketContext } from "@/hooks/use-websocket-context";
-import { fetchServerGroup, fetchService } from "@/lib/nezha-api";
+import {
+	fetchServerGroup,
+	fetchService,
+	isUnauthorizedError,
+} from "@/lib/nezha-api";
 import { cn } from "@/lib/utils";
 import type { NezhaServer, ServerGroup } from "@/types/nezha-api";
 
@@ -53,21 +58,36 @@ const getErrorMessage = (error: unknown) => {
 
 function BackendErrorState({ error }: { error: unknown }) {
 	const { t } = useTranslation();
+	const unauthorized = isUnauthorizedError(error);
 	const message = getErrorMessage(error);
 
 	return (
 		<div className="flex min-h-96 flex-col items-center justify-center px-4 text-center">
 			<div className="flex max-w-md flex-col items-center gap-2">
 				<p className="text-sm font-semibold text-stone-900 dark:text-stone-100">
-					{t("error.backendUnavailableTitle")}
+					{t(
+						unauthorized
+							? "error.loginRequiredTitle"
+							: "error.backendUnavailableTitle",
+					)}
 				</p>
 				<p className="text-sm text-muted-foreground">
-					{t("error.backendUnavailableDescription")}
+					{t(
+						unauthorized
+							? "error.loginRequiredDescription"
+							: "error.backendUnavailableDescription",
+					)}
 				</p>
-				{message && (
-					<p className="mt-1 max-w-full break-words rounded-md bg-stone-100 px-2 py-1 text-xs text-stone-500 dark:bg-stone-800 dark:text-stone-400">
-						{message}
-					</p>
+				{unauthorized ? (
+					<Button asChild className="mt-2">
+						<a href="/dashboard">{t("login")}</a>
+					</Button>
+				) : (
+					message && (
+						<p className="mt-1 max-w-full break-words rounded-md bg-stone-100 px-2 py-1 text-xs text-stone-500 dark:bg-stone-800 dark:text-stone-400">
+							{message}
+						</p>
+					)
 				)}
 			</div>
 		</div>
diff --git a/src/test/lib/nezha-api.test.ts b/src/test/lib/nezha-api.test.ts
index 6e17fe3..6e0792d 100644
--- a/src/test/lib/nezha-api.test.ts
+++ b/src/test/lib/nezha-api.test.ts
@@ -6,6 +6,7 @@ import {
 	fetchServerMetrics,
 	fetchService,
 	fetchSetting,
+	isUnauthorizedError,
 } from "@/lib/nezha-api";
 
 const jsonResponse = (body: unknown, init?: ResponseInit) =>
@@ -52,6 +53,12 @@ describe("nezha api fetchers", () => {
 		await expect(fetchService()).rejects.toThrow("service unavailable");
 	});
 
+	it("detects guest-auth errors from the dashboard API", () => {
+		expect(isUnauthorizedError(new Error("ApiErrorUnauthorized"))).toBe(true);
+		expect(isUnauthorizedError(new Error("settings failed"))).toBe(false);
+		expect(isUnauthorizedError(null)).toBe(false);
+	});
+
 	it("adds monitor and metrics query parameters when periods are provided", async () => {
 		vi.mocked(fetch)
 			.mockResolvedValueOnce(jsonResponse({ success: true, data: [] }))
diff --git a/src/test/pages/Server.test.tsx b/src/test/pages/Server.test.tsx
index 1410718..a54c151 100644
--- a/src/test/pages/Server.test.tsx
+++ b/src/test/pages/Server.test.tsx
@@ -16,7 +16,15 @@ const apiMocks = vi.hoisted(() => ({
 	fetchService: vi.fn(),
 }));
 
-vi.mock("@/lib/nezha-api", () => apiMocks);
+vi.mock("@/lib/nezha-api", async () => {
+	const actual =
+		await vi.importActual<typeof import("@/lib/nezha-api")>("@/lib/nezha-api");
+	return {
+		...actual,
+		fetchServerGroup: apiMocks.fetchServerGroup,
+		fetchService: apiMocks.fetchService,
+	};
+});
 
 vi.mock("@/components/GlobalMap", () => ({
 	default: ({ serverList }: { serverList: NezhaServer[] }) => (
@@ -217,6 +225,32 @@ describe("Servers page", () => {
 		expect(screen.getByText("group failed")).toBeInTheDocument();
 	});
 
+	it("prompts guests to log in when the API returns ApiErrorUnauthorized", async () => {
+		apiMocks.fetchServerGroup.mockRejectedValue(
+			new Error("ApiErrorUnauthorized"),
+		);
+
+		renderServerPage({
+			connected: false,
+			lastData: null,
+		});
+
+		expect(
+			await screen.findByText("error.loginRequiredTitle"),
+		).toBeInTheDocument();
+		expect(
+			screen.getByText("error.loginRequiredDescription"),
+		).toBeInTheDocument();
+		expect(screen.getByRole("link", { name: "login" })).toHaveAttribute(
+			"href",
+			"/dashboard",
+		);
+		expect(
+			screen.queryByText("error.backendUnavailableTitle"),
+		).not.toBeInTheDocument();
+		expect(screen.queryByText("ApiErrorUnauthorized")).not.toBeInTheDocument();
+	});
+
 	it("summarizes online and offline servers from websocket data", async () => {
 		const online = createServer({ id: 1, name: "alpha" });
 		const offline = createServer({