diff --git a/src-tauri/src/auto_updater.rs b/src-tauri/src/auto_updater.rs
index 5196ea8..dbce456 100644
--- a/src-tauri/src/auto_updater.rs
+++ b/src-tauri/src/auto_updater.rs
@@ -702,6 +702,7 @@ mod tests {
       created_by_email: None,
       dns_blocklist: None,
       password_protected: false,
+      created_at: None,
     }
   }
 
diff --git a/src-tauri/src/browser.rs b/src-tauri/src/browser.rs
index 1d94ea9..f287245 100644
--- a/src-tauri/src/browser.rs
+++ b/src-tauri/src/browser.rs
@@ -1219,6 +1219,7 @@ mod tests {
       created_by_email: None,
       dns_blocklist: None,
       password_protected: false,
+      created_at: None,
     };
 
     let path = profile.get_profile_data_path(&profiles_dir);
diff --git a/src-tauri/src/browser_runner.rs b/src-tauri/src/browser_runner.rs
index af123d3..1ba9616 100644
--- a/src-tauri/src/browser_runner.rs
+++ b/src-tauri/src/browser_runner.rs
@@ -7,10 +7,78 @@ use crate::platform_browser;
 use crate::profile::{BrowserProfile, ProfileManager};
 use crate::proxy_manager::PROXY_MANAGER;
 use crate::wayfern_manager::{WayfernConfig, WayfernManager};
+use chrono::{Datelike, TimeZone, Utc};
 use serde::Serialize;
 use std::path::PathBuf;
 use std::time::{Duration, SystemTime, UNIX_EPOCH};
 use sysinfo::System;
+
+/// Fixed UTC hour at which Wayfern fingerprints rotate. Picked to land in a
+/// low-traffic window for the average user; everyone shares the same UTC
+/// instant so the value here doesn't track any one user's local schedule.
+const FINGERPRINT_ROLLOVER_HOUR_UTC: u32 = 4;
+
+/// File name of the per-profile marker recording the last fingerprint
+/// refresh time. Lives at `<profiles_dir>/<profile_id>/.last-fp-refresh`
+/// and is excluded from cloud sync (see `sync::manifest`) so each device
+/// runs its own refresh schedule.
+const LAST_FP_REFRESH_FILE: &str = ".last-fp-refresh";
+
+/// Most recent rollover instant on or before `now` — used as a staleness
+/// threshold for Wayfern fingerprints. Anything generated before this
+/// timestamp is considered stale and gets regenerated on next launch.
+fn most_recent_rollover_epoch() -> u64 {
+  let now = Utc::now();
+  let today_threshold = Utc
+    .with_ymd_and_hms(
+      now.year(),
+      now.month(),
+      now.day(),
+      FINGERPRINT_ROLLOVER_HOUR_UTC,
+      0,
+      0,
+    )
+    .single()
+    .unwrap_or(now);
+  let threshold = if now >= today_threshold {
+    today_threshold
+  } else {
+    today_threshold - chrono::Duration::days(1)
+  };
+  threshold.timestamp().max(0) as u64
+}
+
+fn last_fp_refresh_path(profile_id: &str, profiles_dir: &std::path::Path) -> PathBuf {
+  profiles_dir.join(profile_id).join(LAST_FP_REFRESH_FILE)
+}
+
+/// Read the epoch-seconds timestamp stored in the per-profile refresh marker.
+/// Returns `None` if the file doesn't exist or its content can't be parsed —
+/// both signal "needs a refresh" to the caller.
+fn read_last_fp_refresh(profile_id: &str, profiles_dir: &std::path::Path) -> Option<u64> {
+  let path = last_fp_refresh_path(profile_id, profiles_dir);
+  let content = std::fs::read_to_string(&path).ok()?;
+  content.trim().parse::<u64>().ok()
+}
+
+/// Record `ts` (epoch seconds) as the most recent fingerprint refresh for
+/// this profile. Failure is logged but never propagated — a missing marker
+/// only costs an extra regen on the next launch, never blocks one.
+fn write_last_fp_refresh(profile_id: &str, profiles_dir: &std::path::Path, ts: u64) {
+  let path = last_fp_refresh_path(profile_id, profiles_dir);
+  if let Some(parent) = path.parent() {
+    if !parent.exists() {
+      if let Err(e) = std::fs::create_dir_all(parent) {
+        log::warn!("Failed to create profile dir for fingerprint refresh marker {profile_id}: {e}");
+        return;
+      }
+    }
+  }
+  if let Err(e) = std::fs::write(&path, ts.to_string()) {
+    log::warn!("Failed to write fingerprint refresh marker for {profile_id}: {e}");
+  }
+}
+
 pub struct BrowserRunner {
   pub profile_manager: &'static ProfileManager,
   pub downloaded_browsers_registry: &'static DownloadedBrowsersRegistry,
@@ -544,12 +612,32 @@ impl BrowserRunner {
         wayfern_config.proxy
       );
 
-      // Check if we need to generate a new fingerprint on every launch
+      // Decide whether to (re)generate the Wayfern fingerprint for this
+      // launch. Two triggers:
+      //
+      // 1. `randomize_fingerprint_on_launch = true` — explicit per-launch
+      //    randomization the user opted into.
+      // 2. The fingerprint hasn't been refreshed since the most recent
+      //    rollover instant. We check the per-profile marker file first
+      //    (`.last-fp-refresh`); if it's absent we fall back to
+      //    `profile.created_at` so brand-new profiles don't immediately
+      //    regenerate the fingerprint they were just created with.
+      //    Profiles with neither (truly legacy) are treated as ancient
+      //    and refresh on next launch — once.
       let mut updated_profile = profile.clone();
-      if wayfern_config.randomize_fingerprint_on_launch == Some(true) {
+      let stale_threshold = most_recent_rollover_epoch();
+      let profile_id_str = profile.id.to_string();
+      let profiles_dir_for_marker = self.profile_manager.get_profiles_dir();
+      let effective_last_refresh =
+        read_last_fp_refresh(&profile_id_str, &profiles_dir_for_marker).or(profile.created_at);
+      let is_stale_profile = effective_last_refresh.is_none_or(|ts| ts < stale_threshold);
+      let randomize_every_launch = wayfern_config.randomize_fingerprint_on_launch == Some(true);
+      if randomize_every_launch || is_stale_profile {
         log::info!(
-          "Generating random fingerprint for Wayfern profile: {}",
-          profile.name
+          "Generating Wayfern fingerprint for profile {} (per-launch={}, rollover={})",
+          profile.name,
+          randomize_every_launch,
+          is_stale_profile
         );
 
         // Create a config copy without the existing fingerprint to force generation of a new one
@@ -571,10 +659,24 @@ impl BrowserRunner {
         // Update the config with the new fingerprint for launching
         wayfern_config.fingerprint = Some(new_fingerprint.clone());
 
-        // Save the updated fingerprint to the profile so it persists
+        // Write the marker so the next launch within the same rollover
+        // window skips this branch. The marker is excluded from cloud
+        // sync (see `sync::manifest::DEFAULT_EXCLUDE_PATTERNS`), so each
+        // device's refresh schedule is independent.
+        let now_epoch = SystemTime::now()
+          .duration_since(UNIX_EPOCH)
+          .map(|d| d.as_secs())
+          .unwrap_or(stale_threshold);
+        write_last_fp_refresh(&profile_id_str, &profiles_dir_for_marker, now_epoch);
+
+        // Save the updated fingerprint to the profile so it persists.
         let mut updated_wayfern_config = updated_profile.wayfern_config.clone().unwrap_or_default();
         updated_wayfern_config.fingerprint = Some(new_fingerprint);
-        updated_wayfern_config.randomize_fingerprint_on_launch = Some(true);
+        // Preserve the user's randomize-on-launch preference rather than
+        // forcing it on. The rollover path must not silently flip this
+        // flag for users who only opted into the scheduled refresh.
+        updated_wayfern_config.randomize_fingerprint_on_launch =
+          wayfern_config.randomize_fingerprint_on_launch;
         if wayfern_config.os.is_some() {
           updated_wayfern_config.os = wayfern_config.os.clone();
         }
diff --git a/src-tauri/src/ephemeral_dirs.rs b/src-tauri/src/ephemeral_dirs.rs
index 20bc07e..5808d9c 100644
--- a/src-tauri/src/ephemeral_dirs.rs
+++ b/src-tauri/src/ephemeral_dirs.rs
@@ -280,6 +280,7 @@ mod tests {
       created_by_email: None,
       dns_blocklist: None,
       password_protected: false,
+      created_at: None,
     }
   }
 
diff --git a/src-tauri/src/lib.rs b/src-tauri/src/lib.rs
index 1b600fd..4804c85 100644
--- a/src-tauri/src/lib.rs
+++ b/src-tauri/src/lib.rs
@@ -1161,6 +1161,7 @@ async fn generate_sample_fingerprint(
     created_by_email: None,
     dns_blocklist: None,
     password_protected: false,
+    created_at: None,
   };
 
   if browser == "camoufox" {
diff --git a/src-tauri/src/profile/manager.rs b/src-tauri/src/profile/manager.rs
index c122dc7..dab19e3 100644
--- a/src-tauri/src/profile/manager.rs
+++ b/src-tauri/src/profile/manager.rs
@@ -185,6 +185,7 @@ impl ProfileManager {
           created_by_email: None,
           dns_blocklist: None,
           password_protected: false,
+          created_at: None,
         };
 
         match self
@@ -287,6 +288,7 @@ impl ProfileManager {
           created_by_email: None,
           dns_blocklist: None,
           password_protected: false,
+          created_at: None,
         };
 
         match self
@@ -343,6 +345,12 @@ impl ProfileManager {
       created_by_email: None,
       dns_blocklist,
       password_protected: false,
+      created_at: Some(
+        std::time::SystemTime::now()
+          .duration_since(std::time::UNIX_EPOCH)
+          .map(|d| d.as_secs())
+          .unwrap_or(0),
+      ),
     };
 
     // Save profile info
@@ -989,6 +997,12 @@ impl ProfileManager {
       created_by_email: None,
       dns_blocklist: source.dns_blocklist,
       password_protected: false,
+      created_at: Some(
+        std::time::SystemTime::now()
+          .duration_since(std::time::UNIX_EPOCH)
+          .map(|d| d.as_secs())
+          .unwrap_or(0),
+      ),
     };
 
     self.save_profile(&new_profile)?;
diff --git a/src-tauri/src/profile/password.rs b/src-tauri/src/profile/password.rs
index 944d329..1c309ee 100644
--- a/src-tauri/src/profile/password.rs
+++ b/src-tauri/src/profile/password.rs
@@ -233,6 +233,15 @@ pub async fn set_profile_password(profile_id: String, password: String) -> Resul
     return Err(err_code("PROFILE_ALREADY_PROTECTED"));
   }
 
+  // Ephemeral profiles live in RAM-backed dirs that get wiped on quit, so
+  // there's no on-disk data to encrypt. The two features are mutually
+  // exclusive by design — fail loudly rather than silently producing a
+  // half-broken state where `password_protected` is true but the encrypted
+  // dir vanishes between launches.
+  if profile.ephemeral {
+    return Err(err_code("PROFILE_EPHEMERAL"));
+  }
+
   if profile
     .process_id
     .is_some_and(crate::proxy_storage::is_process_running)
diff --git a/src-tauri/src/profile/types.rs b/src-tauri/src/profile/types.rs
index 30526c1..4e3dfe3 100644
--- a/src-tauri/src/profile/types.rs
+++ b/src-tauri/src/profile/types.rs
@@ -73,6 +73,11 @@ pub struct BrowserProfile {
   /// Decryption goes to a RAM-backed ephemeral dir, never to disk.
   #[serde(default)]
   pub password_protected: bool,
+  /// Profile creation timestamp (epoch seconds, UTC). `None` for legacy
+  /// profiles that pre-date this field — those are treated as ancient by
+  /// any staleness check.
+  #[serde(default)]
+  pub created_at: Option<u64>,
 }
 
 pub fn default_release_type() -> String {
diff --git a/src-tauri/src/profile_importer.rs b/src-tauri/src/profile_importer.rs
index 9a7eef8..51562f8 100644
--- a/src-tauri/src/profile_importer.rs
+++ b/src-tauri/src/profile_importer.rs
@@ -585,6 +585,7 @@ impl ProfileImporter {
           created_by_email: None,
           dns_blocklist: None,
           password_protected: false,
+          created_at: None,
         };
 
         match self
@@ -666,6 +667,7 @@ impl ProfileImporter {
           created_by_email: None,
           dns_blocklist: None,
           password_protected: false,
+          created_at: None,
         };
 
         match self
@@ -718,6 +720,12 @@ impl ProfileImporter {
       created_by_email: None,
       dns_blocklist: None,
       password_protected: false,
+      created_at: Some(
+        std::time::SystemTime::now()
+          .duration_since(std::time::UNIX_EPOCH)
+          .map(|d| d.as_secs())
+          .unwrap_or(0),
+      ),
     };
 
     self.profile_manager.save_profile(&profile)?;
diff --git a/src-tauri/src/sync/manifest.rs b/src-tauri/src/sync/manifest.rs
index 2fccbc8..214f325 100644
--- a/src-tauri/src/sync/manifest.rs
+++ b/src-tauri/src/sync/manifest.rs
@@ -52,6 +52,10 @@ pub const DEFAULT_EXCLUDE_PATTERNS: &[&str] = &[
   "**/BrowserMetrics*",
   "**/.DS_Store",
   ".donut-sync/**",
+  // Local-only marker recording when Wayfern last refreshed this profile's
+  // fingerprint. Each device decides its own refresh cadence, so syncing
+  // this would cause one device's refresh to silence others.
+  ".last-fp-refresh",
 ];
 
 /// A single file entry in the manifest
diff --git a/src/components/profile-data-table.tsx b/src/components/profile-data-table.tsx
index f1ca93b..2a3af32 100644
--- a/src/components/profile-data-table.tsx
+++ b/src/components/profile-data-table.tsx
@@ -1931,9 +1931,7 @@ export function ProfilesDataTable({
           const meta = table.options.meta as TableMeta;
           const profile = row.original;
           const browser = profile.browser;
-          const IconComponent = profile.password_protected
-            ? LuLock
-            : getProfileIcon(profile);
+          const IconComponent = getProfileIcon(profile);
           const isCrossOs = isCrossOsProfile(profile);
 
           const isSelected = meta.isProfileSelected(profile.id);
diff --git a/src/i18n/locales/en.json b/src/i18n/locales/en.json
index 060a855..f952b78 100644
--- a/src/i18n/locales/en.json
+++ b/src/i18n/locales/en.json
@@ -1734,6 +1734,7 @@
     "profileNotProtected": "Profile is not password protected",
     "profileAlreadyProtected": "Profile is already password protected",
     "profileRunning": "Cannot perform this action while the profile is running",
+    "profileEphemeral": "Ephemeral profiles cannot be password-protected — their data wipes on quit.",
     "profileMissingSalt": "Profile is missing its encryption salt",
     "profileLocked": "Profile is locked. Enter the password first.",
     "invalidProfileId": "Invalid profile id",
diff --git a/src/i18n/locales/es.json b/src/i18n/locales/es.json
index a4195ee..b625480 100644
--- a/src/i18n/locales/es.json
+++ b/src/i18n/locales/es.json
@@ -1734,6 +1734,7 @@
     "profileNotProtected": "El perfil no está protegido por contraseña",
     "profileAlreadyProtected": "El perfil ya está protegido por contraseña",
     "profileRunning": "No se puede realizar esta acción mientras el perfil está en ejecución",
+    "profileEphemeral": "Los perfiles efímeros no pueden tener contraseña — sus datos se borran al salir.",
     "profileMissingSalt": "Al perfil le falta su sal de cifrado",
     "profileLocked": "El perfil está bloqueado. Introduce la contraseña primero.",
     "invalidProfileId": "ID de perfil no válido",
diff --git a/src/i18n/locales/fr.json b/src/i18n/locales/fr.json
index e26f2ba..3bb4164 100644
--- a/src/i18n/locales/fr.json
+++ b/src/i18n/locales/fr.json
@@ -1734,6 +1734,7 @@
     "profileNotProtected": "Le profil n'est pas protégé par mot de passe",
     "profileAlreadyProtected": "Le profil est déjà protégé par mot de passe",
     "profileRunning": "Impossible d'effectuer cette action pendant que le profil est en cours d'exécution",
+    "profileEphemeral": "Les profils éphémères ne peuvent pas être protégés par mot de passe — leurs données s'effacent à la fermeture.",
     "profileMissingSalt": "Le sel de chiffrement du profil est manquant",
     "profileLocked": "Le profil est verrouillé. Entrez d'abord le mot de passe.",
     "invalidProfileId": "Identifiant de profil non valide",
diff --git a/src/i18n/locales/ja.json b/src/i18n/locales/ja.json
index 4f74464..b472746 100644
--- a/src/i18n/locales/ja.json
+++ b/src/i18n/locales/ja.json
@@ -1734,6 +1734,7 @@
     "profileNotProtected": "プロファイルはパスワード保護されていません",
     "profileAlreadyProtected": "プロファイルはすでにパスワード保護されています",
     "profileRunning": "プロファイルの実行中はこの操作を実行できません",
+    "profileEphemeral": "エフェメラル プロファイルにはパスワードを設定できません — 終了時にデータが消去されます。",
     "profileMissingSalt": "プロファイルに暗号化ソルトがありません",
     "profileLocked": "プロファイルはロックされています。先にパスワードを入力してください。",
     "invalidProfileId": "無効なプロファイルIDです",
diff --git a/src/i18n/locales/pt.json b/src/i18n/locales/pt.json
index 7efe2e9..43110d0 100644
--- a/src/i18n/locales/pt.json
+++ b/src/i18n/locales/pt.json
@@ -1734,6 +1734,7 @@
     "profileNotProtected": "O perfil não está protegido por senha",
     "profileAlreadyProtected": "O perfil já está protegido por senha",
     "profileRunning": "Não é possível realizar esta ação enquanto o perfil está em execução",
+    "profileEphemeral": "Perfis efêmeros não podem ser protegidos por senha — seus dados são apagados ao sair.",
     "profileMissingSalt": "O perfil está sem o sal de criptografia",
     "profileLocked": "O perfil está bloqueado. Digite a senha primeiro.",
     "invalidProfileId": "ID de perfil inválido",
diff --git a/src/i18n/locales/ru.json b/src/i18n/locales/ru.json
index 2e62bf5..bb34fa7 100644
--- a/src/i18n/locales/ru.json
+++ b/src/i18n/locales/ru.json
@@ -1734,6 +1734,7 @@
     "profileNotProtected": "Профиль не защищён паролем",
     "profileAlreadyProtected": "Профиль уже защищён паролем",
     "profileRunning": "Невозможно выполнить это действие, пока профиль запущен",
+    "profileEphemeral": "Эфемерные профили не могут быть защищены паролем — их данные удаляются при выходе.",
     "profileMissingSalt": "У профиля отсутствует соль шифрования",
     "profileLocked": "Профиль заблокирован. Сначала введите пароль.",
     "invalidProfileId": "Недействительный идентификатор профиля",
diff --git a/src/i18n/locales/zh.json b/src/i18n/locales/zh.json
index 10d6c49..8c22f0a 100644
--- a/src/i18n/locales/zh.json
+++ b/src/i18n/locales/zh.json
@@ -1734,6 +1734,7 @@
     "profileNotProtected": "配置文件未受密码保护",
     "profileAlreadyProtected": "配置文件已受密码保护",
     "profileRunning": "配置文件运行时无法执行此操作",
+    "profileEphemeral": "临时配置文件无法设置密码 — 退出时数据会被清除。",
     "profileMissingSalt": "配置文件缺少加密盐",
     "profileLocked": "配置文件已锁定。请先输入密码。",
     "invalidProfileId": "配置文件 ID 无效",
diff --git a/src/lib/backend-errors.ts b/src/lib/backend-errors.ts
index 71a63e0..9a27aa3 100644
--- a/src/lib/backend-errors.ts
+++ b/src/lib/backend-errors.ts
@@ -11,6 +11,7 @@ export type BackendErrorCode =
   | "PROFILE_NOT_PROTECTED"
   | "PROFILE_ALREADY_PROTECTED"
   | "PROFILE_RUNNING"
+  | "PROFILE_EPHEMERAL"
   | "PROFILE_MISSING_SALT"
   | "PROFILE_LOCKED"
   | "INVALID_PROFILE_ID"
@@ -74,6 +75,8 @@ export function translateBackendError(t: TFunction, err: unknown): string {
       return t("backendErrors.profileAlreadyProtected");
     case "PROFILE_RUNNING":
       return t("backendErrors.profileRunning");
+    case "PROFILE_EPHEMERAL":
+      return t("backendErrors.profileEphemeral");
     case "PROFILE_MISSING_SALT":
       return t("backendErrors.profileMissingSalt");
     case "PROFILE_LOCKED":
diff --git a/src/lib/browser-utils.ts b/src/lib/browser-utils.ts
index c2f8c51..f466a88 100644
--- a/src/lib/browser-utils.ts
+++ b/src/lib/browser-utils.ts
@@ -9,6 +9,7 @@ import {
   FaFire,
   FaFirefox,
 } from "react-icons/fa";
+import { LuLock } from "react-icons/lu";
 
 /**
  * Map internal browser names to display names
@@ -42,7 +43,13 @@ export function getBrowserIcon(browserType: string) {
 export function getProfileIcon(profile: {
   browser: string;
   ephemeral?: boolean;
+  password_protected?: boolean;
 }) {
+  // `password_protected` and `ephemeral` are mutually exclusive (the backend
+  // rejects setting a password on an ephemeral profile), so the order here
+  // doesn't matter — checking lock first only matters if the invariant is
+  // ever violated, in which case showing the lock is the safer default.
+  if (profile.password_protected) return LuLock;
   if (profile.ephemeral) return FaFire;
   return getBrowserIcon(profile.browser);
 }