diff --git a/docs/PLAN.md b/docs/PLAN.md
index f074795..a584ea9 100644
--- a/docs/PLAN.md
+++ b/docs/PLAN.md
@@ -47,3 +47,4 @@ Updated: 2026-04-02
 30. Added a websocket heartbeat so time-based status transitions such as `live -> idle/warn` are recalculated predictably even when no new proxy events arrive.
 31. Moved proxy-copy into the Users actions column, added a last-seen/online column from parsed 3proxy logs, and introduced bounded websocket/API reconnect attempts with a visible connection banner and forced logout after full recovery failure.
 32. Restored proxy-link copying for plain-`http` deployments by falling back from the Clipboard API to `execCommand('copy')`, and added regression coverage for both clipboard paths.
+33. Replaced stale startup mock values with explicit skeleton loading states so the shell no longer flashes fallback dashboard/users/settings data before the first live snapshot arrives.
diff --git a/docs/PROJECT_INDEX.md b/docs/PROJECT_INDEX.md
index 0f9a6ac..6cc539a 100644
--- a/docs/PROJECT_INDEX.md
+++ b/docs/PROJECT_INDEX.md
@@ -23,10 +23,10 @@ Updated: 2026-04-02
 ## Frontend
 
 - `src/main.tsx`: application bootstrap
-- `src/App.tsx`: authenticated panel shell with API-backed login, `sessionStorage` token persistence, hash-based tab history, websocket snapshot patch sync, bounded reconnect/API fallback policy with connection notices, log-derived last-seen user labels, icon-based user actions, HTTP-safe proxy-link copying fallback, create/edit user modal flows, runtime stop control, localized labels, early theme application, and protected panel mutations
+- `src/App.tsx`: authenticated panel shell with API-backed login, `sessionStorage` token persistence, hash-based tab history, websocket snapshot patch sync, bounded reconnect/API fallback policy with connection notices, skeleton-first startup hydration, log-derived last-seen user labels, icon-based user actions, HTTP-safe proxy-link copying fallback, create/edit user modal flows, runtime stop control, localized labels, early theme application, and protected panel mutations
 - `src/SystemTab.tsx`: Settings tab with separate panel-settings and services cards, editable proxy endpoint, dirty-draft protection against incoming live sync, unified service type editing, remove confirmation, and generated config preview
-- `src/App.test.tsx`: login-gate, preferences persistence, hash-tab restoration, websocket-sync safety, reconnect/logout fallback handling, clipboard fallback coverage, generated-credential/create-edit modal flows, runtime stop, pause/resume, delete-confirm, and settings-save UI tests
-- `src/app.css`: full panel styling including fixed-width icon action buttons, busy-state treatment, and connection banner styling
+- `src/App.test.tsx`: login-gate, startup skeleton, preferences persistence, hash-tab restoration, websocket-sync safety, reconnect/logout fallback handling, clipboard fallback coverage, generated-credential/create-edit modal flows, runtime stop, pause/resume, delete-confirm, and settings-save UI tests
+- `src/app.css`: full panel styling including fixed-width icon action buttons, busy-state treatment, startup skeleton shimmer states, and connection banner styling
 - `src/data/mockDashboard.ts`: default panel state and frontend fallback snapshot
 - `src/lib/3proxy.ts`: formatting and status helpers
 - `src/lib/3proxy.test.ts`: paranoia-oriented tests for core domain rules
diff --git a/src/App.test.tsx b/src/App.test.tsx
index 7349189..47c9003 100644
--- a/src/App.test.tsx
+++ b/src/App.test.tsx
@@ -9,6 +9,12 @@ async function loginIntoPanel(user: ReturnType<typeof userEvent.setup>) {
   await user.type(screen.getByLabelText(/login/i), 'admin');
   await user.type(screen.getByLabelText(/password/i), 'proxy-ui-demo');
   await user.click(screen.getByRole('button', { name: /open panel/i }));
+  await waitFor(() => expect(MockWebSocket.instances.length).toBeGreaterThan(0));
+  MockWebSocket.instances.at(-1)?.emitMessage({
+    type: 'snapshot.init',
+    snapshot: fallbackDashboardSnapshot,
+  });
+  await waitFor(() => expect(screen.getByRole('button', { name: /settings/i })).not.toBeDisabled());
 }
 
 function mockClipboardWriteText(writeText: ReturnType<typeof vi.fn>) {
@@ -64,6 +70,19 @@ describe('App login gate', () => {
     expect(screen.queryByRole('button', { name: /open panel/i })).not.toBeInTheDocument();
   });
 
+  it('shows loading skeletons instead of stale mock values before the first snapshot arrives', async () => {
+    const user = userEvent.setup();
+    render(<App />);
+
+    await user.type(screen.getByLabelText(/login/i), 'admin');
+    await user.type(screen.getByLabelText(/password/i), 'proxy-ui-demo');
+    await user.click(screen.getByRole('button', { name: /open panel/i }));
+
+    expect(screen.getByRole('navigation', { name: /primary/i })).toBeInTheDocument();
+    expect(screen.queryByText(/edge\.example\.net/i)).not.toBeInTheDocument();
+    expect(document.querySelectorAll('.skeleton-line').length).toBeGreaterThan(0);
+  });
+
   it('stores panel language in localStorage and restores it after a remount', async () => {
     const user = userEvent.setup();
     const firstRender = render(<App />);
diff --git a/src/App.tsx b/src/App.tsx
index c26d8ef..23045c6 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -831,6 +831,259 @@ function TrashIcon() {
   );
 }
 
+function SkeletonLine({ className = '' }: { className?: string }) {
+  return <span className={`skeleton-line ${className}`.trim()} aria-hidden="true" />;
+}
+
+function ShellLoadingState({
+  activeTab,
+  text,
+}: {
+  activeTab: TabId;
+  text: ReturnType<typeof getPanelText>;
+}) {
+  return (
+    <>
+      <header className="shell-header" aria-busy="true">
+        <div className="shell-title">
+          <h1>3proxy UI</h1>
+          <SkeletonLine className="skeleton-host" />
+        </div>
+        <div className="header-meta">
+          {[text.common.status, text.common.version, text.common.users].map((label) => (
+            <div key={label}>
+              <span>{label}</span>
+              <SkeletonLine className="skeleton-meta-value" />
+            </div>
+          ))}
+          <button type="button" className="button-secondary" disabled>
+            {text.common.signOut}
+          </button>
+        </div>
+      </header>
+
+      <nav className="tabbar" aria-label="Primary">
+        {tabs.map((tab) => (
+          <button
+            key={tab.id}
+            type="button"
+            className={activeTab === tab.id ? 'tab-button active' : 'tab-button'}
+            disabled
+          >
+            {text.tabs[tab.textKey]}
+          </button>
+        ))}
+      </nav>
+
+      {activeTab === 'dashboard' ? <DashboardSkeleton text={text} /> : null}
+      {activeTab === 'users' ? <UsersSkeleton text={text} /> : null}
+      {activeTab === 'system' ? <SystemSkeleton text={text} /> : null}
+    </>
+  );
+}
+
+function DashboardSkeleton({ text }: { text: ReturnType<typeof getPanelText> }) {
+  return (
+    <section className="page-grid" aria-busy="true">
+      <article className="panel-card">
+        <div className="card-header">
+          <h2>{text.dashboard.service}</h2>
+          <SkeletonLine className="skeleton-pill" />
+        </div>
+        <dl className="kv-list">
+          {Array.from({ length: 4 }).map((_, index) => (
+            <div key={index}>
+              <dt><SkeletonLine className="skeleton-label" /></dt>
+              <dd><SkeletonLine className="skeleton-value" /></dd>
+            </div>
+          ))}
+        </dl>
+        <div className="actions-row">
+          <button type="button" disabled>{text.dashboard.start}</button>
+          <button type="button" className="button-secondary" disabled>{text.dashboard.stop}</button>
+          <button type="button" className="button-secondary" disabled>{text.dashboard.restart}</button>
+        </div>
+      </article>
+
+      <article className="panel-card">
+        <div className="card-header">
+          <h2>{text.dashboard.traffic}</h2>
+        </div>
+        <div className="stats-strip">
+          {Array.from({ length: 3 }).map((_, index) => (
+            <div key={index}>
+              <SkeletonLine className="skeleton-label" />
+              <SkeletonLine className="skeleton-value" />
+            </div>
+          ))}
+        </div>
+      </article>
+
+      <article className="panel-card">
+        <div className="card-header">
+          <h2>{text.dashboard.dailyUsage}</h2>
+        </div>
+        <div className="usage-list">
+          {Array.from({ length: 5 }).map((_, index) => (
+            <div key={index} className="usage-row">
+              <SkeletonLine className="skeleton-day" />
+              <div className="usage-bar skeleton-bar-track">
+                <div style={{ width: `${55 + index * 8}%` }} />
+              </div>
+              <SkeletonLine className="skeleton-bytes" />
+            </div>
+          ))}
+        </div>
+      </article>
+
+      <article className="panel-card">
+        <div className="card-header">
+          <h2>{text.dashboard.attention}</h2>
+        </div>
+        <div className="event-list">
+          {Array.from({ length: 3 }).map((_, index) => (
+            <div key={index} className="event-row skeleton-event-row">
+              <span className="event-marker neutral" />
+              <div>
+                <SkeletonLine className="skeleton-value" />
+                <SkeletonLine className="skeleton-copy" />
+              </div>
+            </div>
+          ))}
+        </div>
+      </article>
+    </section>
+  );
+}
+
+function UsersSkeleton({ text }: { text: ReturnType<typeof getPanelText> }) {
+  return (
+    <section className="page-grid single-column" aria-busy="true">
+      <article className="panel-card">
+        <div className="table-toolbar">
+          <div className="toolbar-title">
+            <h2>{text.users.title}</h2>
+            <SkeletonLine className="skeleton-copy short" />
+          </div>
+          <div className="toolbar-actions">
+            <div className="summary-pills">
+              {Array.from({ length: 3 }).map((_, index) => (
+                <span key={index}><SkeletonLine className="skeleton-pill-text" /></span>
+              ))}
+            </div>
+            <button type="button" disabled>{text.users.newUser}</button>
+          </div>
+        </div>
+        <div className="table-wrap">
+          <table>
+            <thead>
+              <tr>
+                <th>{text.users.user}</th>
+                <th>{text.users.endpoint}</th>
+                <th>{text.common.status}</th>
+                <th>{text.users.used}</th>
+                <th>{text.users.remaining}</th>
+                <th>{text.users.online}</th>
+                <th>{text.users.share}</th>
+                <th>{text.users.actions}</th>
+              </tr>
+            </thead>
+            <tbody>
+              {Array.from({ length: 4 }).map((_, index) => (
+                <tr key={index}>
+                  <td><SkeletonLine className="skeleton-copy" /></td>
+                  <td><SkeletonLine className="skeleton-copy" /></td>
+                  <td><SkeletonLine className="skeleton-pill" /></td>
+                  <td><SkeletonLine className="skeleton-inline" /></td>
+                  <td><SkeletonLine className="skeleton-inline" /></td>
+                  <td><SkeletonLine className="skeleton-inline" /></td>
+                  <td><SkeletonLine className="skeleton-inline" /></td>
+                  <td>
+                    <div className="row-actions">
+                      {Array.from({ length: 4 }).map((__, actionIndex) => (
+                        <span key={actionIndex} className="icon-button secondary skeleton-icon-button" aria-hidden="true" />
+                      ))}
+                    </div>
+                  </td>
+                </tr>
+              ))}
+            </tbody>
+          </table>
+        </div>
+      </article>
+    </section>
+  );
+}
+
+function SystemSkeleton({ text }: { text: ReturnType<typeof getPanelText> }) {
+  return (
+    <section className="page-grid single-column system-grid" aria-busy="true">
+      <article className="panel-card">
+        <div className="card-header">
+          <h2>{text.settings.panelTitle}</h2>
+        </div>
+        <div className="panel-settings-grid">
+          <div className="field-group panel-settings-wide">
+            <span>{text.settings.proxyHost}</span>
+            <SkeletonLine className="skeleton-input" />
+          </div>
+          <div className="field-group compact-field">
+            <span>{text.common.language}</span>
+            <SkeletonLine className="skeleton-input" />
+          </div>
+          <div className="field-group compact-field">
+            <span>{text.common.theme}</span>
+            <SkeletonLine className="skeleton-input" />
+          </div>
+        </div>
+      </article>
+
+      <article className="panel-card">
+        <div className="card-header">
+          <h2>{text.settings.title}</h2>
+          <button type="button" className="button-secondary" disabled>{text.common.addService}</button>
+        </div>
+        <div className="service-editor-list">
+          {Array.from({ length: 2 }).map((_, index) => (
+            <section key={index} className="service-editor-row">
+              <div className="service-editor-header">
+                <div>
+                  <SkeletonLine className="skeleton-value" />
+                  <SkeletonLine className="skeleton-inline" />
+                </div>
+                <button type="button" className="button-secondary button-small" disabled>{text.common.remove}</button>
+              </div>
+              <div className="service-editor-grid">
+                {Array.from({ length: 4 }).map((__, fieldIndex) => (
+                  <div key={fieldIndex} className={`field-group${fieldIndex === 3 ? ' field-span-2' : ''}`}>
+                    <SkeletonLine className="skeleton-label" />
+                    <SkeletonLine className="skeleton-input" />
+                  </div>
+                ))}
+              </div>
+            </section>
+          ))}
+        </div>
+        <div className="system-actions">
+          <button type="button" className="button-secondary" disabled>{text.common.reset}</button>
+          <button type="button" disabled>{text.common.saveSettings}</button>
+        </div>
+      </article>
+
+      <article className="panel-card wide-card">
+        <div className="card-header">
+          <h2>{text.settings.generatedConfig}</h2>
+        </div>
+        <div className="config-skeleton">
+          {Array.from({ length: 8 }).map((_, index) => (
+            <SkeletonLine key={index} className={`skeleton-config-line${index % 3 === 0 ? ' long' : ''}`} />
+          ))}
+        </div>
+      </article>
+    </section>
+  );
+}
+
 export default function App() {
   const [preferences, setPreferences] = useState<PanelPreferences>(() => {
     const loaded = loadPanelPreferences();
@@ -841,6 +1094,7 @@ export default function App() {
   const [activeTab, setActiveTab] = useState<TabId>(() => readTabFromHash(window.location.hash));
   const [connectionNotice, setConnectionNotice] = useState<string | null>(null);
   const [snapshot, setSnapshot] = useState<DashboardSnapshot>(fallbackDashboardSnapshot);
+  const [hasSnapshotHydrated, setHasSnapshotHydrated] = useState(false);
   const text = getPanelText(preferences.language);
 
   useEffect(() => {
@@ -874,6 +1128,7 @@ export default function App() {
   const resetSession = () => {
     clearStoredSession();
     setConnectionNotice(null);
+    setHasSnapshotHydrated(false);
     setSession(null);
   };
 
@@ -918,6 +1173,8 @@ export default function App() {
       return;
     }
 
+    setHasSnapshotHydrated(false);
+
     let cancelled = false;
     let reconnectTimer: number | null = null;
     let socket: WebSocket | null = null;
@@ -941,6 +1198,7 @@ export default function App() {
 
         if (!cancelled && payload) {
           setSnapshot(payload);
+          setHasSnapshotHydrated(true);
           return true;
         }
       } catch (error) {
@@ -1043,12 +1301,14 @@ export default function App() {
 
         if (message.type === 'snapshot.init') {
           setSnapshot(message.snapshot);
+          setHasSnapshotHydrated(true);
           setConnectionNotice(null);
           return;
         }
 
         if (message.type === 'snapshot.patch') {
           setSnapshot((current) => applySnapshotPatch(current, message.patch));
+          setHasSnapshotHydrated(true);
           setConnectionNotice(null);
           return;
         }
@@ -1087,6 +1347,15 @@ export default function App() {
     return <LoginGate onUnlock={handleUnlock} preferences={preferences} />;
   }
 
+  if (!hasSnapshotHydrated) {
+    return (
+      <main className="shell">
+        <ShellLoadingState activeTab={activeTab} text={text} />
+        {connectionNotice ? <div className="connection-banner">{connectionNotice}</div> : null}
+      </main>
+    );
+  }
+
   const mutateSnapshot = async (
     request: () => Promise<Response>,
     fallback: (current: DashboardSnapshot) => DashboardSnapshot,
diff --git a/src/app.css b/src/app.css
index 024c43e..f49507e 100644
--- a/src/app.css
+++ b/src/app.css
@@ -191,6 +191,132 @@ button,
   color: #ffffff;
 }
 
+.skeleton-line,
+.skeleton-icon-button {
+  display: inline-flex;
+  border-radius: 8px;
+  background: linear-gradient(
+    90deg,
+    color-mix(in srgb, var(--surface-muted) 82%, transparent) 0%,
+    color-mix(in srgb, var(--border) 85%, var(--surface-muted)) 50%,
+    color-mix(in srgb, var(--surface-muted) 82%, transparent) 100%
+  );
+  background-size: 200% 100%;
+  animation: skeleton-shimmer 1.4s ease-in-out infinite;
+}
+
+.skeleton-host {
+  width: 168px;
+  height: 18px;
+}
+
+.skeleton-meta-value {
+  width: 72px;
+  height: 18px;
+}
+
+.skeleton-label {
+  width: 84px;
+  height: 12px;
+}
+
+.skeleton-value {
+  width: 140px;
+  height: 18px;
+}
+
+.skeleton-copy {
+  width: 180px;
+  height: 16px;
+}
+
+.skeleton-copy.short {
+  width: 120px;
+}
+
+.skeleton-inline {
+  width: 88px;
+  height: 16px;
+}
+
+.skeleton-day {
+  width: 32px;
+  height: 14px;
+}
+
+.skeleton-bytes {
+  width: 72px;
+  height: 16px;
+  justify-self: end;
+}
+
+.skeleton-input {
+  width: 100%;
+  height: 40px;
+}
+
+.skeleton-pill {
+  width: 72px;
+  height: 28px;
+  border-radius: 999px;
+}
+
+.skeleton-pill-text {
+  width: 64px;
+  height: 12px;
+}
+
+.skeleton-bar-track {
+  background: color-mix(in srgb, var(--surface-muted) 75%, var(--border));
+}
+
+.skeleton-bar-track div {
+  background: linear-gradient(
+    90deg,
+    color-mix(in srgb, var(--accent) 28%, var(--surface-muted)) 0%,
+    color-mix(in srgb, var(--accent) 42%, var(--surface-muted)) 100%
+  );
+}
+
+.skeleton-event-row {
+  opacity: 0.92;
+}
+
+.skeleton-config-line {
+  width: 100%;
+  height: 14px;
+}
+
+.skeleton-config-line.long {
+  width: 82%;
+}
+
+.config-skeleton {
+  display: grid;
+  gap: 10px;
+  padding: 14px;
+  border: 1px solid var(--border);
+  border-radius: 10px;
+  background: color-mix(in srgb, var(--surface-muted) 80%, var(--surface));
+}
+
+.skeleton-icon-button {
+  width: 32px;
+  min-width: 32px;
+  height: 32px;
+  border: 1px solid var(--border);
+}
+
+@keyframes skeleton-shimmer {
+  0% {
+    background-position: 100% 50%;
+  }
+
+  100% {
+    background-position: 0% 50%;
+  }
+}
+
 .button-small {
   min-width: 72px;
   height: 32px;
@@ -453,6 +579,10 @@ button,
   background: var(--danger);
 }
 
+.event-marker.neutral {
+  background: var(--border-strong);
+}
+
 .toolbar-title {
   display: grid;
   gap: 4px;