diff --git a/client/src/App.tsx b/client/src/App.tsx
index d316d83..6a6d6bd 100644
--- a/client/src/App.tsx
+++ b/client/src/App.tsx
@@ -97,6 +97,8 @@ function App() {
   const [isDemoMode, setIsDemoMode] = useState(() => window.location.pathname === '/demo')
   const [isAdminRoute, setIsAdminRoute] = useState(() => window.location.pathname.startsWith('/admin'))
   const [isAdminUser, setIsAdminUser] = useState(false)
+  const [sessionChecked, setSessionChecked] = useState(false)
+  const [serverSessionActive, setServerSessionActive] = useState(false)
 
   const syncQueueCount = useLiveQuery(
     () => activeLogbookId ? db.syncQueue.where({ logbookId: activeLogbookId }).count() : db.syncQueue.count(),
@@ -316,6 +318,8 @@ function App() {
         const session = await checkServerSession()
         if (cancelled) return
 
+        setServerSessionActive(session.authenticated)
+
         if (session.authenticated) {
           persistSessionUserId(session.userId)
         }
@@ -335,6 +339,10 @@ function App() {
         if (!cancelled) {
           console.warn('Session restore failed:', err)
         }
+      } finally {
+        if (!cancelled) {
+          setSessionChecked(true)
+        }
       }
     })()
 
@@ -618,7 +626,17 @@ function App() {
   if (!isAuthenticated) {
     return (
       <div className="auth-screen">
-        <AuthOnboarding onAuthenticated={handleAuthenticated} onOpenDemo={openDemo} />
+        {!sessionChecked ? (
+          <div className="auth-card glass">
+            <p className="dashboard-status-msg">{t('auth.restore_checking')}</p>
+          </div>
+        ) : (
+          <AuthOnboarding
+            restoreSession={serverSessionActive}
+            onAuthenticated={handleAuthenticated}
+            onOpenDemo={openDemo}
+          />
+        )}
       </div>
     )
   }
diff --git a/client/src/components/AuthOnboarding.tsx b/client/src/components/AuthOnboarding.tsx
index f0f983e..3262678 100644
--- a/client/src/components/AuthOnboarding.tsx
+++ b/client/src/components/AuthOnboarding.tsx
@@ -1,4 +1,4 @@
-import React, { useState } from 'react'
+import React, { useEffect, useRef, useState } from 'react'
 import { useTranslation } from 'react-i18next'
 import { cycleAppLanguage, getNextLanguage } from '../utils/i18nLanguages.js'
 import {
@@ -12,7 +12,8 @@ import {
   getKnownUsernames,
   forgetUsername,
   hasUnlockedLocalSession,
-  logoutUser
+  logoutUser,
+  resolveRestoreUsername
 } from '../services/auth.js'
 import { KeyRound, ShieldAlert, Languages, HelpCircle, UserRound, X } from 'lucide-react'
 import RegistrationDisclaimer from './RegistrationDisclaimer.tsx'
@@ -27,9 +28,15 @@ import {
 interface AuthOnboardingProps {
   onAuthenticated: () => void
   onOpenDemo?: () => void
+  /** Server session cookie is valid but the in-memory master key was lost (e.g. after reload). */
+  restoreSession?: boolean
 }
 
-export default function AuthOnboarding({ onAuthenticated, onOpenDemo }: AuthOnboardingProps) {
+export default function AuthOnboarding({
+  onAuthenticated,
+  onOpenDemo,
+  restoreSession = false
+}: AuthOnboardingProps) {
   const { t, i18n } = useTranslation()
   const [username, setUsername] = useState('')
   const [loading, setLoading] = useState(false)
@@ -60,7 +67,10 @@ export default function AuthOnboarding({ onAuthenticated, onOpenDemo }: AuthOnbo
   const [isNewRegistration, setIsNewRegistration] = useState(false)
   const [showDisclaimer, setShowDisclaimer] = useState(false)
   const [showHelp, setShowHelp] = useState(false)
+  const [showStandardLogin, setShowStandardLogin] = useState(false)
+  const autoUnlockAttempted = useRef(false)
 
+  const isRestoreFlow = restoreSession && !showStandardLogin
   const passkeyHostOk = isPasskeyCompatibleLocation()
   const passkeyCompatibleUrl = passkeyHostOk ? null : toPasskeyCompatibleUrl(window.location.href)
 
@@ -144,6 +154,23 @@ export default function AuthOnboarding({ onAuthenticated, onOpenDemo }: AuthOnbo
     }
   }
 
+  useEffect(() => {
+    if (!isRestoreFlow || autoUnlockAttempted.current) return
+
+    const user = resolveRestoreUsername()
+    if (user && hasLocalPin(user)) {
+      autoUnlockAttempted.current = true
+      setUsername(user)
+      setShowPinLogin(true)
+      return
+    }
+
+    if (user && passkeyHostOk) {
+      autoUnlockAttempted.current = true
+      void handleLogin(user)
+    }
+  }, [isRestoreFlow, passkeyHostOk])
+
   const handleRecoverySubmit = async (e: React.FormEvent) => {
     e.preventDefault()
     if (!recoveryInput.trim() || !encryptedPayloads) return
@@ -347,10 +374,10 @@ export default function AuthOnboarding({ onAuthenticated, onOpenDemo }: AuthOnbo
       <div className="auth-card glass">
         <div className="auth-header">
           <KeyRound className="auth-icon accent" size={48} />
-          <h2>{t('auth.enter_pin_title')}</h2>
+          <h2>{isRestoreFlow ? t('auth.restore_title') : t('auth.enter_pin_title')}</h2>
         </div>
         <p className="recovery-warning">
-          {t('auth.enter_pin_warning')}
+          {isRestoreFlow ? t('auth.restore_pin_warning') : t('auth.enter_pin_warning')}
         </p>
 
         <form onSubmit={handlePinLoginSubmit} className="auth-form">
@@ -397,6 +424,12 @@ export default function AuthOnboarding({ onAuthenticated, onOpenDemo }: AuthOnbo
               type="button"
               className="btn secondary"
               onClick={() => {
+                if (isRestoreFlow) {
+                  setShowPinLogin(false)
+                  setPinLoginInput('')
+                  setError(null)
+                  return
+                }
                 void (async () => {
                   setShowPinLogin(false)
                   setPinLoginInput('')
@@ -480,6 +513,101 @@ export default function AuthOnboarding({ onAuthenticated, onOpenDemo }: AuthOnbo
     )
   }
 
+  // Render: Session restore (active server cookie, master key lost after reload)
+  if (isRestoreFlow) {
+    const restoreUser = resolveRestoreUsername()
+    const restoreKnownUsers = getKnownUsernames()
+
+    return (
+      <div className="auth-card glass">
+        <div className="auth-header">
+          <KeyRound className="auth-icon accent" size={48} />
+          <h2>{t('auth.restore_title')}</h2>
+        </div>
+        <p className="recovery-warning">{t('auth.restore_subtitle')}</p>
+
+        {loading && (
+          <p className="dashboard-status-msg" style={{ marginTop: '12px' }}>
+            {t('auth.restore_unlocking')}
+          </p>
+        )}
+
+        {error && <div className="auth-error">{error}</div>}
+
+        {!loading && (
+          <div className="auth-actions" style={{ flexDirection: 'column', gap: '10px', marginTop: '16px' }}>
+            {restoreUser && passkeyHostOk && (
+              <button
+                type="button"
+                className="btn primary"
+                onClick={() => handleLogin(restoreUser)}
+                style={{ width: '100%' }}
+              >
+                {t('auth.restore_with_passkey', { name: restoreUser })}
+              </button>
+            )}
+
+            {restoreUser && hasLocalPin(restoreUser) && (
+              <button
+                type="button"
+                className="btn secondary"
+                onClick={() => {
+                  setUsername(restoreUser)
+                  setShowPinLogin(true)
+                }}
+                style={{ width: '100%' }}
+              >
+                {t('auth.restore_with_pin')}
+              </button>
+            )}
+
+            {restoreKnownUsers.length > 1 && (
+              <div style={{ display: 'flex', flexDirection: 'column', gap: '8px', width: '100%' }}>
+                <span style={{ fontSize: '12px', color: '#64748b', textTransform: 'uppercase' }}>
+                  {t('auth.quick_login')}
+                </span>
+                <div style={{ display: 'flex', flexWrap: 'wrap', gap: '8px', width: '100%' }}>
+                  {restoreKnownUsers.map((name) => (
+                    <button
+                      key={name}
+                      type="button"
+                      onClick={() => {
+                        if (hasLocalPin(name)) {
+                          setUsername(name)
+                          setShowPinLogin(true)
+                        } else {
+                          void handleLogin(name)
+                        }
+                      }}
+                      disabled={loading}
+                      className="btn secondary"
+                      style={{ display: 'flex', alignItems: 'center', gap: '6px' }}
+                    >
+                      <UserRound size={16} />
+                      {name}
+                    </button>
+                  ))}
+                </div>
+              </div>
+            )}
+
+            <button
+              type="button"
+              className="btn secondary"
+              onClick={() => {
+                setShowStandardLogin(true)
+                setError(null)
+              }}
+              style={{ width: '100%' }}
+            >
+              {t('auth.restore_other_account')}
+            </button>
+          </div>
+        )}
+      </div>
+    )
+  }
+
   // Render 3: Standard Login / Registration options form
   return (
     <>
diff --git a/client/src/i18n/locales/da.json b/client/src/i18n/locales/da.json
index b1569d4..289d016 100644
--- a/client/src/i18n/locales/da.json
+++ b/client/src/i18n/locales/da.json
@@ -91,7 +91,15 @@
       "use_localhost_link": "Skift til localhost",
       "error_passkey_cancelled": "Passkey-login blev annulleret eller udløb. Prøv igen.",
       "error_invalid_rp_id": "Passkey-domæne matcher ikke (RP ID). Brug http://localhost:5173 med RP_ID=localhost i .env til lokal udvikling.",
-      "error_session_incomplete": "Login ufuldstændig. Log ind med passkey igen."
+      "error_session_incomplete": "Login ufuldstændig. Log ind med passkey igen.",
+      "restore_checking": "Tjekker session…",
+      "restore_title": "Gendan session",
+      "restore_subtitle": "Du er stadig logget ind. Lås din logbog op med passkey eller PIN.",
+      "restore_unlocking": "Låser op…",
+      "restore_with_passkey": "Lås op med passkey ({{name}})",
+      "restore_with_pin": "Lås op med PIN",
+      "restore_pin_warning": "Indtast din lokale PIN for at låse logbogen op efter genindlæsning.",
+      "restore_other_account": "Log ind med en anden konto"
     },
     "pwa": {
       "title": "Installer app",
diff --git a/client/src/i18n/locales/de.json b/client/src/i18n/locales/de.json
index 5b68a3f..5c6ae2a 100644
--- a/client/src/i18n/locales/de.json
+++ b/client/src/i18n/locales/de.json
@@ -91,7 +91,15 @@
       "use_localhost_link": "Zu localhost wechseln",
       "error_passkey_cancelled": "Passkey-Anmeldung abgebrochen oder abgelaufen. Bitte erneut versuchen.",
       "error_invalid_rp_id": "Passkey-Domain passt nicht (RP ID). Lokal nur http://localhost:5173 mit RP_ID=localhost in .env verwenden.",
-      "error_session_incomplete": "Anmeldung unvollständig. Bitte erneut mit Passkey anmelden."
+      "error_session_incomplete": "Anmeldung unvollständig. Bitte erneut mit Passkey anmelden.",
+      "restore_checking": "Session wird geprüft…",
+      "restore_title": "Session wiederherstellen",
+      "restore_subtitle": "Deine Anmeldung ist noch aktiv. Entsperre dein Logbuch mit Passkey oder PIN.",
+      "restore_unlocking": "Wird entsperrt…",
+      "restore_with_passkey": "Mit Passkey entsperren ({{name}})",
+      "restore_with_pin": "Mit PIN entsperren",
+      "restore_pin_warning": "Gib deine lokale PIN ein, um dein Logbuch nach dem Neuladen zu entsperren.",
+      "restore_other_account": "Anderer Account anmelden"
     },
     "pwa": {
       "title": "App installieren",
diff --git a/client/src/i18n/locales/en.json b/client/src/i18n/locales/en.json
index 07f71f2..2a32916 100644
--- a/client/src/i18n/locales/en.json
+++ b/client/src/i18n/locales/en.json
@@ -91,7 +91,15 @@
       "use_localhost_link": "Switch to localhost",
       "error_passkey_cancelled": "Passkey sign-in was cancelled or timed out. Please try again.",
       "error_invalid_rp_id": "Passkey domain mismatch (RP ID). For local dev use http://localhost:5173 with RP_ID=localhost in .env.",
-      "error_session_incomplete": "Sign-in incomplete. Please sign in with your passkey again."
+      "error_session_incomplete": "Sign-in incomplete. Please sign in with your passkey again.",
+      "restore_checking": "Checking session…",
+      "restore_title": "Restore session",
+      "restore_subtitle": "You are still signed in. Unlock your logbook with passkey or PIN.",
+      "restore_unlocking": "Unlocking…",
+      "restore_with_passkey": "Unlock with passkey ({{name}})",
+      "restore_with_pin": "Unlock with PIN",
+      "restore_pin_warning": "Enter your local PIN to unlock your logbook after reload.",
+      "restore_other_account": "Sign in with another account"
     },
     "pwa": {
       "title": "Install app",
diff --git a/client/src/i18n/locales/nb.json b/client/src/i18n/locales/nb.json
index 1a06508..b01f7ff 100644
--- a/client/src/i18n/locales/nb.json
+++ b/client/src/i18n/locales/nb.json
@@ -91,7 +91,15 @@
       "use_localhost_link": "Bytt til localhost",
       "error_passkey_cancelled": "Passkey-innlogging ble avbrutt eller utløp. Prøv igjen.",
       "error_invalid_rp_id": "Passkey-domene stemmer ikke (RP ID). Bruk http://localhost:5173 med RP_ID=localhost i .env for lokal utvikling.",
-      "error_session_incomplete": "Innlogging ufullstendig. Logg inn med passkey igjen."
+      "error_session_incomplete": "Innlogging ufullstendig. Logg inn med passkey igjen.",
+      "restore_checking": "Sjekker økt…",
+      "restore_title": "Gjenopprett økt",
+      "restore_subtitle": "Du er fortsatt innlogget. Lås opp loggboken med passkey eller PIN.",
+      "restore_unlocking": "Låser opp…",
+      "restore_with_passkey": "Lås opp med passkey ({{name}})",
+      "restore_with_pin": "Lås opp med PIN",
+      "restore_pin_warning": "Skriv inn din lokale PIN for å låse opp loggboken etter omlasting.",
+      "restore_other_account": "Logg inn med en annen konto"
     },
     "pwa": {
       "title": "Installer app",
diff --git a/client/src/i18n/locales/sv.json b/client/src/i18n/locales/sv.json
index 557bd8f..7f7641c 100644
--- a/client/src/i18n/locales/sv.json
+++ b/client/src/i18n/locales/sv.json
@@ -91,7 +91,15 @@
       "use_localhost_link": "Byt till localhost",
       "error_passkey_cancelled": "Passkey-inloggning avbröts eller gick ut. Försök igen.",
       "error_invalid_rp_id": "Passkey-domänen matchar inte (RP ID). Använd http://localhost:5173 med RP_ID=localhost i .env för lokal utveckling.",
-      "error_session_incomplete": "Inloggning ofullständig. Logga in med passkey igen."
+      "error_session_incomplete": "Inloggning ofullständig. Logga in med passkey igen.",
+      "restore_checking": "Kontrollerar session…",
+      "restore_title": "Återställ session",
+      "restore_subtitle": "Du är fortfarande inloggad. Lås upp din loggbok med passkey eller PIN.",
+      "restore_unlocking": "Låser upp…",
+      "restore_with_passkey": "Lås upp med passkey ({{name}})",
+      "restore_with_pin": "Lås upp med PIN",
+      "restore_pin_warning": "Ange din lokala PIN för att låsa upp loggboken efter omladdning.",
+      "restore_other_account": "Logga in med ett annat konto"
     },
     "pwa": {
       "title": "Installera app",
diff --git a/client/src/services/auth.ts b/client/src/services/auth.ts
index 15bed59..5693450 100644
--- a/client/src/services/auth.ts
+++ b/client/src/services/auth.ts
@@ -64,6 +64,15 @@ export function persistSessionUserId(userId: string | undefined): void {
   }
 }
 
+/** Username to use when re-unlocking after reload (active account or sole remembered user). */
+export function resolveRestoreUsername(): string | null {
+  const stored = localStorage.getItem('active_username')
+  if (stored) return stored
+  const known = getKnownUsernames()
+  if (known.length === 1) return known[0]
+  return null
+}
+
 export async function reauthWithPasskey(): Promise<boolean> {
   const options = await apiJson<any>(`${API_BASE}/reauth-options`, {
     method: 'POST'
diff --git a/client/src/services/authSession.test.ts b/client/src/services/authSession.test.ts
index 9f1fc07..272378b 100644
--- a/client/src/services/authSession.test.ts
+++ b/client/src/services/authSession.test.ts
@@ -2,6 +2,7 @@ import { beforeEach, describe, expect, it } from 'vitest'
 import {
   hasUnlockedLocalCrypto,
   hasUnlockedLocalSession,
+  resolveRestoreUsername,
   setActiveMasterKey
 } from './auth.js'
 
@@ -33,6 +34,28 @@ describe('local session unlock checks', () => {
   })
 })
 
+describe('resolveRestoreUsername', () => {
+  beforeEach(() => {
+    localStorage.clear()
+  })
+
+  it('prefers active_username from storage', () => {
+    localStorage.setItem('active_username', 'captain')
+    localStorage.setItem('daagbox_known_users', JSON.stringify(['other']))
+    expect(resolveRestoreUsername()).toBe('captain')
+  })
+
+  it('falls back to a single remembered user', () => {
+    localStorage.setItem('daagbox_known_users', JSON.stringify(['solo']))
+    expect(resolveRestoreUsername()).toBe('solo')
+  })
+
+  it('returns null when multiple users and no active username', () => {
+    localStorage.setItem('daagbox_known_users', JSON.stringify(['alpha', 'beta']))
+    expect(resolveRestoreUsername()).toBeNull()
+  })
+})
+
 describe('persistSessionUserId', () => {
   beforeEach(() => {
     localStorage.clear()