diff --git a/browser_cli/__init__.py b/browser_cli/__init__.py
index f0b3644..00d9607 100644
--- a/browser_cli/__init__.py
+++ b/browser_cli/__init__.py
@@ -117,6 +117,10 @@ class BrowserCLI:
     def focus_url(self, pattern: str) -> None:
         self._cmd("navigate.focus", {"pattern": pattern})
 
+    def navigate_tab(self, tab_id: int, url: str) -> None:
+        """Navigate a specific tab to *url*."""
+        self._cmd("navigate.to", {"tabId": tab_id, "url": url})
+
     # ── Search ────────────────────────────────────────────────────────────
 
     def search(
@@ -168,6 +172,13 @@ class BrowserCLI:
         """Switch browser focus to a tab by ID."""
         self._cmd("tabs.active", {"tabId": tab_id})
 
+    def window_active_tab(self, window_id: int) -> Tab:
+        """Return active tab for a specific browser window."""
+        data = self._cmd("tabs.active_in_window", {"windowId": window_id})
+        if not isinstance(data, dict) or "id" not in data:
+            raise RuntimeError(f"No active tab found for window {window_id}")
+        return self._make_tab(data)
+
     def tabs_filter(self, pattern_or_filter: str | Callable[[Tab], bool] | Callable[[list[Tab]], Iterable[Tab]]) -> list[Tab]:
         """Return tabs filtered by pattern or a Python callable."""
         if isinstance(pattern_or_filter, str):
diff --git a/browser_cli/models.py b/browser_cli/models.py
index 8064a5c..0f18224 100644
--- a/browser_cli/models.py
+++ b/browser_cli/models.py
@@ -87,11 +87,8 @@ class Tab:
         return self._b()._cmd("tabs.html", {"tabId": self.id})
 
     def open(self, url: str, *, background: bool = False) -> None:
-        """Navigate this tab to *url*."""
-        # Re-uses navigate.open which opens a new tab; for in-place navigation
-        # we target by tabId via the focus then navigate approach. For now we
-        # open a new tab in the same window as a convenience.
-        self._b()._cmd("navigate.open", {"url": url, "background": background})
+        """Navigate this tab to *url* in place."""
+        self._b().navigate_tab(self.id, url)
 
 
 # ── Group ─────────────────────────────────────────────────────────────────────
diff --git a/extension/background.js b/extension/background.js
index 1f440d2..ce6f4b3 100644
--- a/extension/background.js
+++ b/extension/background.js
@@ -121,6 +121,7 @@ async function dispatch(command, args) {
   switch (command) {
     // ── Navigation ────────────────────────────────────────────────────────
     case "navigate.open":    return navOpen(args);
+    case "navigate.to":      return navTo(args);
     case "navigate.reload":  return navReload(args, false);
     case "navigate.hard_reload": return navReload(args, true);
     case "navigate.back":    return navBack(args);
@@ -132,6 +133,7 @@ async function dispatch(command, args) {
     case "tabs.close":        return tabsClose(args);
     case "tabs.move":         return tabsMove(args);
     case "tabs.active":       return tabsActive(args);
+    case "tabs.active_in_window": return tabsActiveInWindow(args);
     case "tabs.filter":       return tabsFilter(args);
     case "tabs.count":        return tabsCount(args);
     case "tabs.query":        return tabsQuery(args);
@@ -191,9 +193,11 @@ async function dispatch(command, args) {
 
 // ── Navigation ────────────────────────────────────────────────────────────────
 
-async function navOpen({ url, background, window: windowName, group: groupNameOrId }) {
+async function navOpen({ url, background, window: windowName, windowId: explicitWindowId, group: groupNameOrId }) {
   let windowId;
-  if (windowName) {
+  if (explicitWindowId != null) {
+    windowId = explicitWindowId;
+  } else if (windowName) {
     const aliases = await getAliases();
     const entry = Object.entries(aliases).find(([, v]) => v === windowName);
     if (entry) windowId = parseInt(entry[0]);
@@ -221,6 +225,11 @@ async function navOpen({ url, background, window: windowName, group: groupNameOr
   return { id: tab.id, url: tab.url };
 }
 
+async function navTo({ tabId, url }) {
+  const tab = await chrome.tabs.update(tabId, { url });
+  return { id: tab.id, url: tab.url || url };
+}
+
 async function navReload({ tabId }, bypassCache) {
   const tab = tabId ? { id: tabId } : await getActiveTab();
   await chrome.tabs.reload(tab.id, { bypassCache });
@@ -326,6 +335,15 @@ async function tabsActive({ tabId }) {
   return { tabId };
 }
 
+async function tabsActiveInWindow({ windowId }) {
+  const activeTabs = await chrome.tabs.query({ windowId, active: true });
+  const tab = activeTabs[0];
+  if (!tab) {
+    throw new Error(`No active tab found for window ${windowId}`);
+  }
+  return tabInfo(tab);
+}
+
 async function tabsFilter({ pattern }) {
   const all = await chrome.tabs.query({});
   return all.filter(t => t.url && t.url.includes(pattern)).map(tabInfo);
diff --git a/extension/manifest.json b/extension/manifest.json
index 0d6def5..18dce74 100644
--- a/extension/manifest.json
+++ b/extension/manifest.json
@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "browser-cli",
-  "version": "0.5.7",
+  "version": "0.5.8",
   "description": "Control your browser from the terminal via browser-cli",
   "permissions": [
     "tabs",
diff --git a/pyproject.toml b/pyproject.toml
index d7d37bd..54867c8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "browser-cli"
-version = "0.5.7"
+version = "0.5.8"
 description = "Control your real running browser from the terminal via a Chrome extension"
 requires-python = ">=3.10"
 dependencies = [
diff --git a/tests/test_api.py b/tests/test_api.py
index 202b34f..d2d05dd 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -154,6 +154,12 @@ class TestNavigation:
         b.focus_url("github.com")
         mock_send.assert_called_once_with("navigate.focus", {"pattern": "github.com"}, profile=None)
 
+    def test_navigate_tab(self, b, mock_send):
+        b.navigate_tab(5, "https://example.com")
+        mock_send.assert_called_once_with(
+            "navigate.to", {"tabId": 5, "url": "https://example.com"}, profile=None
+        )
+
     def test_profile_forwarded(self, b_profile, mock_send):
         b_profile.reload()
         mock_send.assert_called_once_with("navigate.reload", {"tabId": None}, profile="brave")
@@ -244,6 +250,18 @@ class TestTabs:
         b.tabs_active(10)
         mock_send.assert_called_once_with("tabs.active", {"tabId": 10}, profile=None)
 
+    def test_window_active_tab(self, b, mock_send):
+        mock_send.return_value = TAB_DATA
+        tab = b.window_active_tab(1)
+        assert isinstance(tab, Tab)
+        assert tab.id == 10
+        mock_send.assert_called_once_with("tabs.active_in_window", {"windowId": 1}, profile=None)
+
+    def test_window_active_tab_missing_raises(self, b, mock_send):
+        mock_send.return_value = None
+        with pytest.raises(RuntimeError, match="No active tab found for window 1"):
+            b.window_active_tab(1)
+
     def test_tabs_filter(self, b, mock_send):
         mock_send.return_value = [TAB_DATA]
         tabs = b.tabs_filter("example")
@@ -564,7 +582,15 @@ class TestTabModel:
     def test_open(self, tab, mock_send):
         tab.open("https://new.example.com")
         mock_send.assert_called_once_with(
-            "navigate.open", {"url": "https://new.example.com", "background": False}, profile=None
+            "navigate.to", {"tabId": 10, "url": "https://new.example.com"}, profile=None
+        )
+
+    def test_open_background_changes_same_tab(self, tab, mock_send):
+        tab.open("https://new.example.com", background=True)
+        mock_send.assert_called_once_with(
+            "navigate.to",
+            {"tabId": 10, "url": "https://new.example.com"},
+            profile=None,
         )
 
     def test_unbound_raises(self):
diff --git a/tests/test_nav.py b/tests/test_nav.py
index db37caa..20d2728 100644
--- a/tests/test_nav.py
+++ b/tests/test_nav.py
@@ -81,3 +81,24 @@ def test_nav_open_in_background(browser):
         assert not new_tab.get("active"), "background tab should not be active"
     finally:
         browser("tabs.close", {"tabId": new_id})
+
+
+def test_nav_to_updates_existing_tab(browser):
+    result = browser("navigate.open", {"url": "https://example.com", "background": True})
+    tab_id = result["id"]
+
+    try:
+        before_ids = {t["id"] for t in browser("tabs.list")}
+        updated = browser("navigate.to", {"tabId": tab_id, "url": "https://example.org"})
+        assert updated["id"] == tab_id
+
+        tabs = browser("tabs.list")
+        after_ids = {t["id"] for t in tabs}
+        assert after_ids == before_ids
+        tab = next(t for t in tabs if t["id"] == tab_id)
+        assert "example.org" in (tab.get("url") or "")
+    finally:
+        try:
+            browser("tabs.close", {"tabId": tab_id})
+        except Exception:
+            pass
diff --git a/tests/test_tabs.py b/tests/test_tabs.py
index 9264c27..669b82c 100644
--- a/tests/test_tabs.py
+++ b/tests/test_tabs.py
@@ -44,6 +44,13 @@ def test_tabs_active_exists(browser):
     assert len(active) >= 1, "Expected at least one active tab"
 
 
+def test_tabs_active_in_window(browser):
+    active = next(t for t in browser("tabs.list") if t.get("active"))
+    result = browser("tabs.active_in_window", {"windowId": active["windowId"]})
+    assert result["id"] == active["id"]
+    assert result["windowId"] == active["windowId"]
+
+
 def test_tabs_html(browser, http_tab):
     html = browser("tabs.html", {"tabId": http_tab["id"]})
     assert isinstance(html, str)