diff --git a/public/index.html b/public/index.html
index c9d967c..4b706a9 100644
--- a/public/index.html
+++ b/public/index.html
@@ -664,6 +664,95 @@
       font-weight: 600;
     }
 
+    .popover {
+      position: fixed;
+      top: 60px;
+      right: 200px;
+      background: #2a2a2a;
+      border: 1px solid #3a3a3a;
+      border-radius: 8px;
+      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
+      z-index: 1500;
+      min-width: 300px;
+      max-width: 400px;
+    }
+
+    .popover-content {
+      padding: 0;
+    }
+
+    .popover-header {
+      padding: 12px 16px;
+      border-bottom: 1px solid #3a3a3a;
+      font-size: 14px;
+      font-weight: 600;
+      color: #e0e0e0;
+    }
+
+    #session-filter-list {
+      max-height: 400px;
+      overflow-y: auto;
+    }
+
+    .session-filter-item {
+      padding: 12px 16px;
+      border-bottom: 1px solid #3a3a3a;
+      cursor: pointer;
+      transition: background 0.2s;
+    }
+
+    .session-filter-item:last-child {
+      border-bottom: none;
+    }
+
+    .session-filter-item:hover {
+      background: rgba(255, 255, 255, 0.05);
+    }
+
+    .session-filter-item.selected {
+      background: rgba(255, 152, 0, 0.1);
+      border-left: 3px solid #ff9800;
+      padding-left: 13px;
+    }
+
+    .session-filter-command {
+      font-weight: 600;
+      font-size: 13px;
+      margin-bottom: 4px;
+      display: flex;
+      align-items: center;
+      gap: 8px;
+    }
+
+    .session-filter-cwd {
+      font-size: 11px;
+      color: #888;
+      overflow: hidden;
+      text-overflow: ellipsis;
+      white-space: nowrap;
+    }
+
+    .clear-filter-btn {
+      width: 100%;
+      padding: 12px 16px;
+      border: none;
+      border-top: 1px solid #3a3a3a;
+      background: #1a1a1a;
+      color: #e0e0e0;
+      font-size: 13px;
+      font-weight: 500;
+      cursor: pointer;
+      transition: background 0.2s;
+    }
+
+    .clear-filter-btn:hover {
+      background: rgba(255, 255, 255, 0.05);
+    }
+
+    .clear-filter-btn:active {
+      opacity: 0.7;
+    }
+
     @media (prefers-color-scheme: light) {
       body {
         background: #f5f5f5;
@@ -742,6 +831,9 @@
   <header>
     <h1>claude-remote</h1>
     <div style="display: flex; align-items: center; gap: 16px;">
+      <button class="settings-btn" id="sessions-filter-btn" onclick="openSessionFilter()" title="Session Filter" style="font-size: 14px; font-weight: 500; min-width: auto; padding: 8px 12px;">
+        <span id="sessions-count-text">0 sessions</span>
+      </button>
       <button class="settings-btn" onclick="openStyleModal()" title="Display Settings">⚙️</button>
       <div class="status" id="status">
         <span class="status-dot"></span>
@@ -750,6 +842,14 @@
     </div>
   </header>
 
+  <div id="session-filter-popover" class="popover" style="display: none;">
+    <div class="popover-content">
+      <div class="popover-header">Select Session</div>
+      <div id="session-filter-list"></div>
+      <button class="clear-filter-btn" onclick="clearSessionFilter()">Show All Sessions</button>
+    </div>
+  </div>
+
   <div class="container">
     <div class="section">
       <div class="section-title">Active Sessions</div>
@@ -1145,12 +1245,29 @@
     }
 
     function renderSessions() {
+      // Update sessions count button text
+      updateSessionsCountButton();
+
       if (state.sessions.size === 0) {
         $sessions.innerHTML = '<div class="empty-state">No active sessions</div>';
         return;
       }
 
-      $sessions.innerHTML = Array.from(state.sessions.values()).map(s => `
+      // Filter sessions if focusSessionId is set
+      let sessionsToRender = Array.from(state.sessions.values());
+      if (state.settings.focusSessionId !== null) {
+        const focusSession = state.sessions.get(state.settings.focusSessionId);
+        if (focusSession) {
+          sessionsToRender = [focusSession];
+        } else {
+          // Filtered session no longer exists, clear filter
+          state.settings.focusSessionId = null;
+          saveSettings();
+          updateSessionsCountButton();
+        }
+      }
+
+      $sessions.innerHTML = sessionsToRender.map(s => `
         <div class="session ${s.expanded ? 'expanded' : ''}" data-session="${s.id}">
           <div class="session-header" onclick="toggleSession('${s.id}')">
             <div class="session-info">
@@ -1723,6 +1840,81 @@
       updateSettingsUI();
     };
 
+    // Session filtering
+    function updateSessionsCountButton() {
+      const $countText = document.getElementById('sessions-count-text');
+      const total = state.sessions.size;
+
+      if (state.settings.focusSessionId !== null) {
+        $countText.innerHTML = `Viewing 1 of ${total} <span style="margin-left: 4px;">×</span>`;
+      } else {
+        const label = total === 1 ? 'session' : 'sessions';
+        $countText.textContent = `${total} ${label}`;
+      }
+    }
+
+    window.openSessionFilter = () => {
+      renderSessionFilterList();
+      const $popover = document.getElementById('session-filter-popover');
+      $popover.style.display = 'block';
+
+      // Close on outside click
+      setTimeout(() => {
+        document.addEventListener('click', closeSessionFilterOnOutsideClick);
+      }, 0);
+    };
+
+    window.closeSessionFilter = () => {
+      const $popover = document.getElementById('session-filter-popover');
+      $popover.style.display = 'none';
+      document.removeEventListener('click', closeSessionFilterOnOutsideClick);
+    };
+
+    function closeSessionFilterOnOutsideClick(event) {
+      const $popover = document.getElementById('session-filter-popover');
+      const $filterBtn = document.getElementById('sessions-filter-btn');
+
+      if (!$popover.contains(event.target) && !$filterBtn.contains(event.target)) {
+        closeSessionFilter();
+      }
+    }
+
+    window.setSessionFilter = (sessionId) => {
+      state.settings.focusSessionId = Number(sessionId);
+      saveSettings();
+      closeSessionFilter();
+      renderSessions();
+    };
+
+    window.clearSessionFilter = () => {
+      state.settings.focusSessionId = null;
+      saveSettings();
+      closeSessionFilter();
+      renderSessions();
+    };
+
+    function renderSessionFilterList() {
+      const $list = document.getElementById('session-filter-list');
+
+      if (state.sessions.size === 0) {
+        $list.innerHTML = '<div style="padding: 16px; text-align: center; color: #888;">No active sessions</div>';
+        return;
+      }
+
+      $list.innerHTML = Array.from(state.sessions.values()).map(s => {
+        const isSelected = state.settings.focusSessionId === s.id;
+        return `
+          <div class="session-filter-item ${isSelected ? 'selected' : ''}" onclick="setSessionFilter(${s.id})">
+            <div class="session-filter-command">
+              <span>${escapeHtml(s.command || 'claude')}</span>
+              ${renderStateBadge(s.state || 'ready')}
+            </div>
+            <div class="session-filter-cwd">${escapeHtml(s.cwd || '~')}</div>
+          </div>
+        `;
+      }).join('');
+    }
+
     // Initialize
     loadSettings();
     applySettings();