diff --git a/browser/ui/ai_chat/BUILD.gn b/browser/ui/ai_chat/BUILD.gn
index 08fe8f927b1c..429b16e73a3a 100644
--- a/browser/ui/ai_chat/BUILD.gn
+++ b/browser/ui/ai_chat/BUILD.gn
@@ -35,3 +35,26 @@ source_set("unit_tests") {
     "//testing/gtest:gtest",
   ]
 }
+
+source_set("browser_tests") {
+  testonly = true
+
+  sources = []
+
+  if (!is_android) {
+    sources += [ "tab_informer_browsertest.cc" ]
+  }
+
+  defines = [ "HAS_OUT_OF_PROC_TEST_RUNNER" ]
+
+  deps = [
+    "//base/test:test_support",
+    "//brave/components/ai_chat/content/browser",
+    "//brave/components/ai_chat/core/browser",
+    "//brave/components/ai_chat/core/common",
+    "//brave/components/ai_chat/core/common/mojom",
+    "//chrome/browser/ui",
+    "//chrome/test:test_support",
+    "//testing/gtest",
+  ]
+}
diff --git a/browser/ui/ai_chat/tab_informer.h b/browser/ui/ai_chat/tab_informer.h
index 065218844bcc..f54c43a709ef 100644
--- a/browser/ui/ai_chat/tab_informer.h
+++ b/browser/ui/ai_chat/tab_informer.h
@@ -50,6 +50,8 @@ class TabInformer : public mojom::TabInformer,
   bool ShouldTrackBrowser(Browser* browser) override;
 
  private:
+  friend class TabInformerBrowserTest;
+
   State GetState();
   void NotifyListeners();
   void NotifyListener(mojom::TabListener* listener, State state);
diff --git a/browser/ui/ai_chat/tab_informer_browsertest.cc b/browser/ui/ai_chat/tab_informer_browsertest.cc
new file mode 100644
index 000000000000..ab51d99668e2
--- /dev/null
+++ b/browser/ui/ai_chat/tab_informer_browsertest.cc
@@ -0,0 +1,211 @@
+// Copyright (c) 2025 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+#include "brave/browser/ui/ai_chat/tab_informer.h"
+
+#include <memory>
+#include <vector>
+
+#include "base/functional/callback_forward.h"
+#include "base/run_loop.h"
+#include "base/test/bind.h"
+#include "brave/components/ai_chat/core/common/mojom/tab_informer.mojom-forward.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_commands.h"
+#include "chrome/browser/ui/browser_tabstrip.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/test/browser_test.h"
+#include "mojo/public/cpp/bindings/pending_remote.h"
+#include "mojo/public/cpp/bindings/self_owned_receiver.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace ai_chat {
+
+namespace {
+
+using Predicate =
+    base::RepeatingCallback<bool(const std::vector<mojom::WindowPtr>&)>;
+
+class UpdateTracker : public mojom::TabListener {
+ public:
+  UpdateTracker() = default;
+  ~UpdateTracker() override = default;
+
+  const std::vector<mojom::WindowPtr>& GetLastWindows() const {
+    CHECK(last_windows_.has_value());
+    return last_windows_.value();
+  }
+
+  void WaitFor(Predicate predicate) {
+    if (last_windows_ && predicate.Run(last_windows_.value())) {
+      return;
+    }
+
+    base::RunLoop waiter;
+    on_change_ = base::BindLambdaForTesting([&]() {
+      if (!last_windows_) {
+        return;
+      }
+      if (predicate.Run(last_windows_.value())) {
+        waiter.Quit();
+        on_change_.Reset();
+      }
+    });
+
+    waiter.Run();
+  }
+
+ private:
+  void TabsChanged(std::vector<mojom::WindowPtr> windows) override {
+    last_windows_ = std::move(windows);
+
+    if (!on_change_.is_null()) {
+      on_change_.Run();
+    }
+  }
+
+  base::RepeatingClosure on_change_;
+  std::optional<std::vector<mojom::WindowPtr>> last_windows_;
+  std::unique_ptr<base::RunLoop> run_loop_;
+};
+
+}  // namespace
+
+class TabInformerBrowserTest : public InProcessBrowserTest {
+ public:
+  TabInformerBrowserTest() = default;
+  ~TabInformerBrowserTest() override = default;
+
+  void SetUpOnMainThread() override {
+    InProcessBrowserTest::SetUpOnMainThread();
+
+    mojo::PendingReceiver<mojom::TabInformer> receiver;
+    tab_informer_ = std::make_unique<TabInformer>(
+        std::move(receiver),
+        browser()->tab_strip_model()->GetActiveWebContents());
+
+    auto listener = std::make_unique<UpdateTracker>();
+    tracker_ = listener.get();
+
+    mojo::PendingRemote<mojom::TabListener> pending_remote;
+    mojo::MakeSelfOwnedReceiver(
+        std::move(listener), pending_remote.InitWithNewPipeAndPassReceiver());
+    tab_informer_->AddListener(std::move(pending_remote));
+  }
+
+  void TearDownOnMainThread() override {
+    tracker_ = nullptr;
+    tab_informer_.reset();
+
+    InProcessBrowserTest::SetUpOnMainThread();
+  }
+
+  const std::vector<mojom::WindowPtr>& GetLastWindows() const {
+    return tracker_->GetLastWindows();
+  }
+
+  void WaitFor(Predicate predicate) { tracker_->WaitFor(std::move(predicate)); }
+
+ protected:
+  void AppendTab(std::string url) {
+    chrome::AddTabAt(browser(), GURL(url), -1, false);
+  }
+
+  std::unique_ptr<TabInformer> tab_informer_;
+  raw_ptr<UpdateTracker> tracker_;
+};
+
+IN_PROC_BROWSER_TEST_F(TabInformerBrowserTest, GetsInitialTabs) {
+  WaitFor(base::BindLambdaForTesting(
+      [](const std::vector<mojom::WindowPtr>& windows) {
+        return windows.size() == 1;
+      }));
+
+  const auto& windows = GetLastWindows();
+
+  // Should be have no tabs because we exclude the owner tab
+  EXPECT_EQ(windows[0]->tabs.size(), 0u);
+}
+
+IN_PROC_BROWSER_TEST_F(TabInformerBrowserTest, TabsChange) {
+  AppendTab("https://google.com");
+  AppendTab("https://brave.com");
+  WaitFor(base::BindLambdaForTesting(
+      [](const std::vector<mojom::WindowPtr>& windows) {
+        return windows.size() == 1 && windows.at(0)->tabs.size() == 2;
+      }));
+
+  {
+    const auto& windows = GetLastWindows();
+    EXPECT_EQ(windows[0]->tabs[0]->url, GURL("https://google.com"));
+    EXPECT_EQ(windows[0]->tabs[1]->url, GURL("https://brave.com"));
+  }
+
+  // Close all tabs but the one we're bound to
+  chrome::CloseOtherTabs(browser());
+
+  WaitFor(base::BindLambdaForTesting(
+      [](const std::vector<mojom::WindowPtr>& windows) {
+        return windows.size() == 1 && windows.at(0)->tabs.size() == 0;
+      }));
+
+  {
+    const auto& updated_windows = GetLastWindows();
+    EXPECT_EQ(updated_windows[0]->tabs.size(), 0u);
+  }
+}
+
+IN_PROC_BROWSER_TEST_F(TabInformerBrowserTest, MultipleWindows) {
+  AppendTab("https://topos.nz");
+  WaitFor(base::BindLambdaForTesting(
+      [](const std::vector<mojom::WindowPtr>& windows) {
+        return windows.size() == 1 && windows.at(0)->tabs.size() == 1;
+      }));
+
+  {
+    const auto& windows = GetLastWindows();
+    EXPECT_EQ(windows[0]->tabs[0]->url, GURL("https://topos.nz"));
+  }
+
+  chrome::NewWindow(browser());
+  WaitFor(base::BindLambdaForTesting(
+      [](const std::vector<mojom::WindowPtr>& windows) {
+        return windows.size() == 2 && windows.at(0)->tabs.size() == 1 &&
+               windows.at(1)->tabs.size() == 0;
+      }));
+
+  AppendTab("https://brave.com");
+  AppendTab("https://readr.nz");
+  WaitFor(base::BindLambdaForTesting(
+      [](const std::vector<mojom::WindowPtr>& windows) {
+        return windows.size() == 2 && windows.at(0)->tabs.size() == 3 &&
+               windows.at(1)->tabs.size() == 0;
+      }));
+
+  chrome::MoveTabsToNewWindow(browser(), {2, 3});
+  WaitFor(base::BindLambdaForTesting(
+      [](const std::vector<mojom::WindowPtr>& windows) {
+        LOG(ERROR) << "Window 0: " << windows.at(0)->tabs.size()
+                   << ", Window 1: " << windows.at(1)->tabs.size();
+        return windows.size() == 3 && windows.at(0)->tabs.size() == 1 &&
+               windows.at(1)->tabs.size() == 0 &&
+               windows.at(2)->tabs.size() == 2;
+      }));
+
+  {
+    const auto& windows = GetLastWindows();
+
+    // Just topos.nz - first tab is bound to the TabInformer
+    EXPECT_EQ(windows[0]->tabs[0]->url, GURL("https://topos.nz"));
+
+    // readr.nz, brave.com
+    EXPECT_EQ(windows[2]->tabs[1]->url, GURL("https://readr.nz"));
+    EXPECT_EQ(windows[2]->tabs[0]->url, GURL("https://brave.com"));
+  }
+}
+
+}  // namespace ai_chat
diff --git a/components/ai_chat/core/browser/ai_chat_service.cc b/components/ai_chat/core/browser/ai_chat_service.cc
index 6354eedad3b3..fee41287acb5 100644
--- a/components/ai_chat/core/browser/ai_chat_service.cc
+++ b/components/ai_chat/core/browser/ai_chat_service.cc
@@ -159,8 +159,7 @@ ConversationHandler* AIChatService::CreateConversation() {
         conversation_uuid, "", base::Time::Now(), false, std::nullopt,
         mojom::SiteInfo::New(base::Uuid::GenerateRandomV4().AsLowercaseString(),
                              mojom::ContentType::PageContent, std::nullopt,
-                             std::nullopt, -1, std::nullopt, 0, false,
-                             false));
+                             std::nullopt, -1, std::nullopt, 0, false, false));
     conversations_.insert_or_assign(conversation_uuid, std::move(conversation));
   }
   mojom::Conversation* conversation =
diff --git a/ios/browser/api/ai_chat/BUILD.gn b/ios/browser/api/ai_chat/BUILD.gn
index d7752a042108..2d4497e0e9c9 100644
--- a/ios/browser/api/ai_chat/BUILD.gn
+++ b/ios/browser/api/ai_chat/BUILD.gn
@@ -69,6 +69,7 @@ ios_objc_mojom_wrappers("ai_chat_mojom_wrappers") {
   mojom_target = "//brave/components/ai_chat/core/common/mojom"
   sources = [
     "//brave/components/ai_chat/core/common/mojom/ai_chat.mojom",
+    "//brave/components/ai_chat/core/common/mojom/tab_informer.mojom",
     "//brave/components/ai_chat/core/common/mojom/untrusted_frame.mojom",
   ]
   output_dir = "$root_gen_dir/brave/components/ai_chat/core/common/mojom/ios"
@@ -86,5 +87,6 @@ ios_objc_mojom_wrappers("ai_chat_mojom_wrappers") {
     "UntrustedConversationHandler",
     "UntrustedConversationUI",
     "UntrustedUIHandler",
+    "TabInformer",
   ]
 }
diff --git a/test/BUILD.gn b/test/BUILD.gn
index 2605215d0c6c..972431215b12 100644
--- a/test/BUILD.gn
+++ b/test/BUILD.gn
@@ -866,6 +866,7 @@ test("brave_browser_tests") {
     "//brave/browser/test:browser_tests",
     "//brave/browser/themes",
     "//brave/browser/ui:browser_tests",
+    "//brave/browser/ui/ai_chat:browser_tests",
     "//brave/browser/ui/tabs/test:browser_tests",
     "//brave/browser/ui/views/tabs:browser_tests",
     "//brave/browser/ui/webui:browser_tests",