diff --git a/web/src/api/request.ts b/web/src/api/request.ts
index a0f81523..7341b4a8 100644
--- a/web/src/api/request.ts
+++ b/web/src/api/request.ts
@@ -6,7 +6,6 @@ const API_BASE = '/api'
 // Toast debounce mechanism - prevent toast spam (5 seconds)
 const toastDebounceMap = new Map<string, number>()
 const TOAST_DEBOUNCE_TIME = 5000
-let sessionExpiredNotified = false
 
 function shouldShowToast(key: string): boolean {
   const now = Date.now()
@@ -84,24 +83,10 @@ export async function request<T>(
       const message = getErrorMessage(data, `HTTP ${response.status}`)
       const normalized = message.toLowerCase()
       const isNotAuthenticated = normalized.includes('not authenticated')
-      if (response.status === 401 && !sessionExpiredNotified) {
-        const isLoggedInElsewhere = normalized.includes('logged in elsewhere')
-        const isSessionExpired = normalized.includes('session expired')
-        if (isLoggedInElsewhere || isSessionExpired) {
-          sessionExpiredNotified = true
-          const titleKey = isLoggedInElsewhere ? 'auth.loggedInElsewhere' : 'auth.sessionExpired'
-          if (toastOnError && shouldShowToast('error_session_expired')) {
-            toast.error(t(titleKey), {
-              description: message,
-              duration: 3000,
-            })
-          }
-          setTimeout(() => {
-            window.location.reload()
-          }, 1200)
-        }
-      }
-      if (toastOnError && shouldShowToast(toastKey) && !(response.status === 401 && isNotAuthenticated)) {
+      const isSessionExpired = normalized.includes('session expired')
+      const isLoggedInElsewhere = normalized.includes('logged in elsewhere')
+      const isAuthIssue = response.status === 401 && (isNotAuthenticated || isSessionExpired || isLoggedInElsewhere)
+      if (toastOnError && shouldShowToast(toastKey) && !isAuthIssue) {
         toast.error(t('api.operationFailed'), {
           description: message,
           duration: 4000,
diff --git a/web/src/router/index.ts b/web/src/router/index.ts
index a3eb97b9..2f617e4e 100644
--- a/web/src/router/index.ts
+++ b/web/src/router/index.ts
@@ -1,4 +1,7 @@
 import { createRouter, createWebHistory, type RouteRecordRaw } from 'vue-router'
+import { toast } from 'vue-sonner'
+import i18n from '@/i18n'
+import { ApiError } from '@/api/request'
 import { useAuthStore } from '@/stores/auth'
 
 const routes: RouteRecordRaw[] = [
@@ -33,6 +36,12 @@ const router = createRouter({
   routes,
 })
 
+let sessionExpiredNotified = false
+
+function t(key: string, params?: Record<string, unknown>): string {
+  return String(i18n.global.t(key, params as any))
+}
+
 // Navigation guard
 router.beforeEach(async (to, _from, next) => {
   const authStore = useAuthStore()
@@ -54,8 +63,21 @@ router.beforeEach(async (to, _from, next) => {
     if (!authStore.isAuthenticated) {
       try {
         await authStore.checkAuth()
-      } catch {
+      } catch (e) {
         // Not authenticated
+        if (e instanceof ApiError && e.status === 401 && !sessionExpiredNotified) {
+          const normalized = e.message.toLowerCase()
+          const isLoggedInElsewhere = normalized.includes('logged in elsewhere')
+          const isSessionExpired = normalized.includes('session expired')
+          if (isLoggedInElsewhere || isSessionExpired) {
+            sessionExpiredNotified = true
+            const titleKey = isLoggedInElsewhere ? 'auth.loggedInElsewhere' : 'auth.sessionExpired'
+            toast.error(t(titleKey), {
+              description: e.message,
+              duration: 3000,
+            })
+          }
+        }
       }
 
       if (!authStore.isAuthenticated) {
diff --git a/web/src/stores/auth.ts b/web/src/stores/auth.ts
index ca8da71e..45684943 100644
--- a/web/src/stores/auth.ts
+++ b/web/src/stores/auth.ts
@@ -32,10 +32,14 @@ export const useAuthStore = defineStore('auth', () => {
       user.value = result.user || null
       isAdmin.value = result.is_admin ?? false
       return result
-    } catch {
+    } catch (e) {
       isAuthenticated.value = false
       user.value = null
       isAdmin.value = false
+      error.value = e instanceof Error ? e.message : 'Not authenticated'
+      if (e instanceof Error) {
+        throw e
+      }
       throw new Error('Not authenticated')
     }
   }