diff --git a/SampleApps/WebView2APISample/AppWindow.cpp b/SampleApps/WebView2APISample/AppWindow.cpp
index f692d5ce..aae3d6b5 100644
--- a/SampleApps/WebView2APISample/AppWindow.cpp
+++ b/SampleApps/WebView2APISample/AppWindow.cpp
@@ -32,6 +32,7 @@
 #include "ScenarioAuthentication.h"
 #include "ScenarioClientCertificateRequested.h"
 #include "ScenarioCookieManagement.h"
+#include "ScenarioCustomDataPartition.h"
 #include "ScenarioCustomDownloadExperience.h"
 #include "ScenarioCustomScheme.h"
 #include "ScenarioCustomSchemeNavigate.h"
@@ -537,6 +538,11 @@ bool AppWindow::ExecuteWebViewCommands(WPARAM wParam, LPARAM lParam)
         NewComponent<ScenarioWebRtcUdpPortConfiguration>(this);
         return true;
     }
+    case IDM_SCENARIO_CUSTOM_DATA_PARTITION:
+    {
+        NewComponent<ScenarioCustomDataPartition>(this);
+        return true;
+    }
     case IDM_SCENARIO_ADD_HOST_OBJECT:
     {
         NewComponent<ScenarioAddHostObject>(this);
@@ -2314,7 +2320,6 @@ void AppWindow::RegisterEventHandlers()
             {
                 if (!m_shouldHandleNewWindowRequest)
                 {
-                    args->put_Handled(FALSE);
                     return S_OK;
                 }
                 wil::com_ptr<ICoreWebView2NewWindowRequestedEventArgs> args_as_comptr = args;
diff --git a/SampleApps/WebView2APISample/ScenarioCustomDataPartition.cpp b/SampleApps/WebView2APISample/ScenarioCustomDataPartition.cpp
new file mode 100644
index 00000000..3bb7ee0f
--- /dev/null
+++ b/SampleApps/WebView2APISample/ScenarioCustomDataPartition.cpp
@@ -0,0 +1,502 @@
+// Copyright (C) Microsoft Corporation. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "stdafx.h"
+
+#include "ScenarioCustomDataPartition.h"
+
+#include "AppWindow.h"
+#include "CheckFailure.h"
+
+using namespace Microsoft::WRL;
+
+static constexpr WCHAR c_samplePath[] = L"ScenarioCustomDataPartition.html";
+static constexpr int c_minNewWindowSize = 100;
+static constexpr WCHAR c_childWindowClassName[] = L"ScenarioCustomDataPartitionChildHostWindow";
+
+static RECT GetPopupWindowRectFromUri(const std::wstring& uri)
+{
+    int left = 100;
+    int top = 100;
+    int width = 800;
+    int height = 600;
+
+    if (uri.find(L"ScenarioCustomDataPartitionChild.html") != std::wstring::npos)
+    {
+        width = 600;
+        height = 800;
+    }
+
+    if (width < c_minNewWindowSize)
+    {
+        width = c_minNewWindowSize;
+    }
+    if (height < c_minNewWindowSize)
+    {
+        height = c_minNewWindowSize;
+    }
+
+    RECT rect = {left, top, left + width, top + height};
+    return rect;
+}
+
+bool ScenarioCustomDataPartition::EnsureChildWindowClassRegistered()
+{
+    static bool s_registered = false;
+    if (s_registered)
+    {
+        return true;
+    }
+
+    WNDCLASSEXW windowClass = {};
+    windowClass.cbSize = sizeof(WNDCLASSEXW);
+    windowClass.style = CS_HREDRAW | CS_VREDRAW;
+    windowClass.lpfnWndProc = ScenarioCustomDataPartition::ChildWndProcStatic;
+    windowClass.hInstance = GetModuleHandle(nullptr);
+    windowClass.hCursor = LoadCursor(nullptr, IDC_ARROW);
+    windowClass.hbrBackground = reinterpret_cast<HBRUSH>(COLOR_WINDOW + 1);
+    windowClass.lpszClassName = c_childWindowClassName;
+
+    if (!RegisterClassExW(&windowClass))
+    {
+        DWORD error = GetLastError();
+        if (error != ERROR_CLASS_ALREADY_EXISTS)
+        {
+            return false;
+        }
+    }
+
+    s_registered = true;
+    return true;
+}
+
+LRESULT CALLBACK ScenarioCustomDataPartition::ChildWndProcStatic(
+    HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
+{
+    if (message == WM_NCCREATE)
+    {
+        auto* createStruct = reinterpret_cast<CREATESTRUCTW*>(lParam);
+        auto* self = reinterpret_cast<ScenarioCustomDataPartition*>(createStruct->lpCreateParams);
+        SetWindowLongPtr(hWnd, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(self));
+    }
+
+    auto* self = reinterpret_cast<ScenarioCustomDataPartition*>(GetWindowLongPtr(hWnd, GWLP_USERDATA));
+    if (self)
+    {
+        return self->ChildWndProc(hWnd, message, wParam, lParam);
+    }
+    return DefWindowProc(hWnd, message, wParam, lParam);
+}
+
+LRESULT ScenarioCustomDataPartition::ChildWndProc(
+    HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
+{
+    switch (message)
+    {
+    case WM_CLOSE:
+        CloseChildWindow();
+        return 0;
+    case WM_SIZE:
+        ResizeChildWebView();
+        break;
+    case WM_DESTROY:
+        if (hWnd == m_childWindow)
+        {
+            m_childWindow = nullptr;
+            m_childController = nullptr;
+            m_childWebView = nullptr;
+        }
+        break;
+    }
+
+    return DefWindowProc(hWnd, message, wParam, lParam);
+}
+
+void ScenarioCustomDataPartition::ResizeChildWebView()
+{
+    if (!m_childWindow || !m_childController)
+    {
+        return;
+    }
+
+    RECT bounds = {};
+    if (GetClientRect(m_childWindow, &bounds))
+    {
+        CHECK_FAILURE(m_childController->put_Bounds(bounds));
+    }
+}
+
+void ScenarioCustomDataPartition::CloseChildWindow()
+{
+    if (m_childWebView && m_childWebMessageReceivedToken.value != 0)
+    {
+        m_childWebView->remove_WebMessageReceived(m_childWebMessageReceivedToken);
+        m_childWebMessageReceivedToken = {};
+    }
+
+    if (m_childController)
+    {
+        m_childController->Close();
+        m_childController = nullptr;
+    }
+    m_childWebView = nullptr;
+
+    if (m_childWindow)
+    {
+        HWND childWindow = m_childWindow;
+        m_childWindow = nullptr;
+        DestroyWindow(childWindow);
+    }
+}
+
+ScenarioCustomDataPartition::ScenarioCustomDataPartition(AppWindow* appWindow)
+    : m_appWindow(appWindow), m_webView(appWindow->GetWebView())
+{
+    m_sampleUri = m_appWindow->GetLocalUri(c_samplePath);
+
+    // Disable host-level popup handling so this scenario can fully own NewWindowRequested.
+    m_appWindow->EnableHandlingNewWindowRequest(false);
+
+    // Register event handlers
+    RegisterEventHandlers();
+
+    // Navigate to the sample page
+    CHECK_FAILURE(m_webView->Navigate(m_sampleUri.c_str()));
+}
+
+void ScenarioCustomDataPartition::RegisterEventHandlers()
+{
+    // Turn off this scenario if we navigate away from the sample page
+    CHECK_FAILURE(m_webView->add_ContentLoading(
+        Callback<ICoreWebView2ContentLoadingEventHandler>(
+            [this](ICoreWebView2* sender, ICoreWebView2ContentLoadingEventArgs* args) -> HRESULT
+            {
+                wil::unique_cotaskmem_string uri;
+                sender->get_Source(&uri);
+                if (uri.get() != m_sampleUri)
+                {
+                    m_appWindow->DeleteComponent(this);
+                }
+                return S_OK;
+            })
+            .Get(),
+        &m_contentLoadingToken));
+
+    // Handle messages from the HTML UI
+    CHECK_FAILURE(m_webView->add_WebMessageReceived(
+        Callback<ICoreWebView2WebMessageReceivedEventHandler>(
+            [this](ICoreWebView2* sender, ICoreWebView2WebMessageReceivedEventArgs* args) -> HRESULT
+            {
+                wil::unique_cotaskmem_string message;
+                CHECK_FAILURE(args->TryGetWebMessageAsString(&message));
+                HandleWebMessage(message.get());
+                return S_OK;
+            })
+            .Get(),
+        &m_webMessageReceivedToken));
+
+    //! [CustomDataPartitionNewWindowRequested]
+    // Register a handler for the NewWindowRequested event.
+    // This handler captures child windows by creating them and setting partitions.
+    CHECK_FAILURE(m_webView->add_NewWindowRequested(
+        Callback<ICoreWebView2NewWindowRequestedEventHandler>(
+            [this](ICoreWebView2* sender, ICoreWebView2NewWindowRequestedEventArgs* args) -> HRESULT
+            {
+                // Get a deferral - we'll complete this asynchronously
+                wil::com_ptr<ICoreWebView2Deferral> deferral;
+                CHECK_FAILURE(args->GetDeferral(&deferral));
+
+                wil::com_ptr<ICoreWebView2NewWindowRequestedEventArgs> argsAsComPtr = args;
+
+                if (m_childWindow || m_childController)
+                {
+                    CloseChildWindow();
+                }
+
+                wil::unique_cotaskmem_string uri;
+                CHECK_FAILURE(args->get_Uri(&uri));
+                std::wstring targetUri = uri.get() ? uri.get() : L"";
+
+                RECT popupRect = GetPopupWindowRectFromUri(targetUri);
+
+                if (!EnsureChildWindowClassRegistered())
+                {
+                    SendStatusToUI(L"Error: Failed to register child window class.");
+                    CHECK_FAILURE(argsAsComPtr->put_Handled(FALSE));
+                    CHECK_FAILURE(deferral->Complete());
+                    return S_OK;
+                }
+
+                m_childWindow = CreateWindowExW(
+                    WS_EX_CONTROLPARENT, c_childWindowClassName,
+                    L"Custom Data Partition Child Window",
+                    WS_OVERLAPPEDWINDOW | WS_CLIPSIBLINGS | WS_CLIPCHILDREN, popupRect.left,
+                    popupRect.top, popupRect.right - popupRect.left,
+                    popupRect.bottom - popupRect.top, nullptr, nullptr,
+                    GetModuleHandle(nullptr), this);
+
+                if (!m_childWindow)
+                {
+                    SendStatusToUI(L"Error: Failed to create child native window.");
+                    CHECK_FAILURE(argsAsComPtr->put_Handled(FALSE));
+                    CHECK_FAILURE(deferral->Complete());
+                    return S_OK;
+                }
+
+                ShowWindow(m_childWindow, SW_SHOWNORMAL);
+                UpdateWindow(m_childWindow);
+
+                auto environment = m_appWindow->GetWebViewEnvironment();
+                if (!environment)
+                {
+                    SendStatusToUI(L"Error: WebView2 environment not available for child window.");
+                    CloseChildWindow();
+                    CHECK_FAILURE(argsAsComPtr->put_Handled(FALSE));
+                    CHECK_FAILURE(deferral->Complete());
+                    return S_OK;
+                }
+
+                CHECK_FAILURE(environment->CreateCoreWebView2Controller(
+                    m_childWindow,
+                    Callback<ICoreWebView2CreateCoreWebView2ControllerCompletedHandler>(
+                        [this, argsAsComPtr, deferral, targetUri](
+                            HRESULT result, ICoreWebView2Controller* controller) -> HRESULT
+                        {
+                            if (result == S_OK && controller)
+                            {
+                                m_childController = controller;
+                                CHECK_FAILURE(m_childController->get_CoreWebView2(&m_childWebView));
+                                SetPartitionOnLastChild(L"DefaultPartitionForChild");
+                                CHECK_FAILURE(m_childWebView->add_WebMessageReceived(
+                                    Callback<ICoreWebView2WebMessageReceivedEventHandler>(
+                                        [this](
+                                            ICoreWebView2* sender,
+                                            ICoreWebView2WebMessageReceivedEventArgs* args)
+                                            -> HRESULT
+                                        {
+                                            wil::unique_cotaskmem_string message;
+                                            CHECK_FAILURE(args->TryGetWebMessageAsString(&message));
+
+                                            if (std::wstring(message.get()) == L"getCustomPartition")
+                                            {
+                                                wil::com_ptr<ICoreWebView2Experimental20>
+                                                    webViewExperimental;
+                                                webViewExperimental =
+                                                    m_childWebView.try_query<
+                                                        ICoreWebView2Experimental20>();
+
+                                                if (!webViewExperimental)
+                                                {
+                                                    SendStatusToChildUI(
+                                                        L"Error: Custom partition API unavailable.");
+                                                    return S_OK;
+                                                }
+
+                                                wil::unique_cotaskmem_string partitionId;
+                                                HRESULT partitionHr =
+                                                    webViewExperimental
+                                                        ->get_CustomDataPartitionId(&partitionId);
+
+                                                if (SUCCEEDED(partitionHr))
+                                                {
+                                                    if (partitionId.get() == nullptr ||
+                                                        wcslen(partitionId.get()) == 0)
+                                                    {
+                                                        SendStatusToChildUI(
+                                                            L"Child partition: (default/none)");
+                                                    }
+                                                    else
+                                                    {
+                                                        std::wstring status =
+                                                            L"Child partition: '" +
+                                                            std::wstring(partitionId.get()) +
+                                                            L"'";
+                                                        SendStatusToChildUI(status);
+                                                    }
+                                                }
+                                                else
+                                                {
+                                                    SendStatusToChildUI(
+                                                        L"Error: Failed to read child partition.");
+                                                }
+                                            }
+
+                                            return S_OK;
+                                        })
+                                        .Get(),
+                                    &m_childWebMessageReceivedToken));
+
+                                auto childWebView3 = m_childWebView.try_query<ICoreWebView2_3>();
+                                if (childWebView3)
+                                {
+                                    CHECK_FAILURE(childWebView3->SetVirtualHostNameToFolderMapping(
+                                        L"appassets.example", L"assets",
+                                        COREWEBVIEW2_HOST_RESOURCE_ACCESS_KIND_DENY_CORS));
+                                }
+
+                                ResizeChildWebView();
+                                CHECK_FAILURE(argsAsComPtr->put_NewWindow(m_childWebView.get()));
+                                CHECK_FAILURE(argsAsComPtr->put_Handled(TRUE));
+                                if (!targetUri.empty())
+                                {
+                                    CHECK_FAILURE(m_childWebView->Navigate(targetUri.c_str()));
+                                }
+                                SendStatusToUI(
+                                    L"Child window created and captured! Ready to set partition.");
+                            }
+                            else
+                            {
+                                CloseChildWindow();
+                                SendStatusToUI(
+                                    L"Error: Failed to create child WebView controller.");
+                                CHECK_FAILURE(argsAsComPtr->put_Handled(FALSE));
+                            }
+
+                            CHECK_FAILURE(deferral->Complete());
+                            return S_OK;
+                        })
+                        .Get()));
+
+                return S_OK;
+            })
+            .Get(),
+        &m_newWindowRequestedToken));
+    //! [CustomDataPartitionNewWindowRequested]
+}
+
+void ScenarioCustomDataPartition::HandleWebMessage(const std::wstring& message)
+{
+    // Parse simple command messages from JavaScript
+    if (message.find(L"setPartition:") == 0)
+    {
+        // Extract partition ID from message
+        std::wstring partitionId = message.substr(13); // Skip "setPartition:"
+        SetPartitionOnLastChild(partitionId);
+    }
+    else if (message == L"checkPartition")
+    {
+        CheckCurrentPartition();
+    }
+}
+
+void ScenarioCustomDataPartition::SetPartitionOnLastChild(const std::wstring& partitionId)
+{
+    if (!m_childWebView)
+    {
+        SendStatusToUI(L"Error: No child window available. Create a child window first.");
+        return;
+    }
+
+    //! [CustomDataPartitionSet]
+    // Try to set custom data partition using the experimental API
+    wil::com_ptr<ICoreWebView2Experimental20> webViewExperimental;
+    webViewExperimental = m_childWebView.try_query<ICoreWebView2Experimental20>();
+
+    if (!webViewExperimental)
+    {
+        SendStatusToUI(L"Error: Custom data partition API (ICoreWebView2Experimental20) not available in this WebView2 version.");
+        return;
+    }
+
+    // Set the partition ID on the child window
+    HRESULT hr = webViewExperimental->put_CustomDataPartitionId(partitionId.c_str());
+    //! [CustomDataPartitionSet]
+
+    if (SUCCEEDED(hr))
+    {
+        std::wstring status = L"✓ Success! Partition '" + partitionId +
+                             L"' set on child window.";
+        SendStatusToUI(status);
+    }
+    else
+    {
+        SendStatusToUI(L"Error: Failed to set custom data partition.");
+    }
+}
+
+void ScenarioCustomDataPartition::CheckCurrentPartition()
+{
+    //! [CustomDataPartitionGet]
+    // Check the partition of the parent window (should be empty/default)
+    wil::com_ptr<ICoreWebView2Experimental20> webViewExperimental;
+    webViewExperimental = m_webView.try_query<ICoreWebView2Experimental20>();
+
+    if (!webViewExperimental)
+    {
+        SendStatusToUI(L"Error: Custom data partition API not available.");
+        return;
+    }
+
+    wil::unique_cotaskmem_string partitionId;
+    HRESULT hr = webViewExperimental->get_CustomDataPartitionId(&partitionId);
+    //! [CustomDataPartitionGet]
+
+    if (SUCCEEDED(hr))
+    {
+        if (partitionId.get() == nullptr || wcslen(partitionId.get()) == 0)
+        {
+            SendStatusToUI(L"✓ Parent window partition: (default/none) - Correct! Parent has no custom partition.");
+        }
+        else
+        {
+            std::wstring status = L"⚠ Parent window partition: '" + std::wstring(partitionId.get()) +
+                                 L"' (Note: Parent should typically remain in default partition)";
+            SendStatusToUI(status);
+        }
+    }
+    else
+    {
+        SendStatusToUI(L"Error: Failed to get partition ID.");
+    }
+}
+
+void ScenarioCustomDataPartition::SendStatusToUI(const std::wstring& status)
+{
+    // Send status message back to the HTML UI
+    // Escape single quotes in the status message
+    std::wstring escapedStatus = status;
+    size_t pos = 0;
+    while ((pos = escapedStatus.find(L"'", pos)) != std::wstring::npos)
+    {
+        escapedStatus.replace(pos, 1, L"\\'");
+        pos += 2;
+    }
+
+    std::wstring script = L"updateStatus('" + escapedStatus + L"');";
+    CHECK_FAILURE(m_webView->ExecuteScript(script.c_str(), nullptr));
+}
+
+void ScenarioCustomDataPartition::SendStatusToChildUI(const std::wstring& status)
+{
+    if (!m_childWebView)
+    {
+        return;
+    }
+
+    std::wstring escapedStatus = status;
+    size_t pos = 0;
+    while ((pos = escapedStatus.find(L"'", pos)) != std::wstring::npos)
+    {
+        escapedStatus.replace(pos, 1, L"\\'");
+        pos += 2;
+    }
+
+    std::wstring script = L"updateChildPartitionStatus('" + escapedStatus + L"');";
+    CHECK_FAILURE(m_childWebView->ExecuteScript(script.c_str(), nullptr));
+}
+
+ScenarioCustomDataPartition::~ScenarioCustomDataPartition()
+{
+    // Restore default host-level popup handling.
+    if (m_appWindow)
+    {
+        m_appWindow->EnableHandlingNewWindowRequest(true);
+    }
+
+    CloseChildWindow();
+
+    m_webView->remove_ContentLoading(m_contentLoadingToken);
+    m_webView->remove_WebMessageReceived(m_webMessageReceivedToken);
+    m_webView->remove_NewWindowRequested(m_newWindowRequestedToken);
+}
diff --git a/SampleApps/WebView2APISample/ScenarioCustomDataPartition.h b/SampleApps/WebView2APISample/ScenarioCustomDataPartition.h
new file mode 100644
index 00000000..00cf23ca
--- /dev/null
+++ b/SampleApps/WebView2APISample/ScenarioCustomDataPartition.h
@@ -0,0 +1,60 @@
+// Copyright (C) Microsoft Corporation. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#pragma once
+#include "stdafx.h"
+
+#include <string>
+
+#include "AppWindow.h"
+#include "ComponentBase.h"
+
+// This component demonstrates custom data partition management for child windows.
+// It shows how to:
+// 1. Create child windows and capture them via NewWindowRequested event
+// 2. Apply custom data partitions to child windows only (not parent)
+// 3. Create blob URLs from images in the parent window
+// 4. Test blob URL accessibility across partition boundaries
+//
+// Key pattern: In NewWindowRequested handler:
+//   1. Get deferral
+//   2. Create a native window for the popup
+//   3. Create a WebView controller for that window
+//   4. In controller-created callback, provide args->put_NewWindow(childWebView)
+//   5. Complete deferral
+class ScenarioCustomDataPartition : public ComponentBase
+{
+public:
+    ScenarioCustomDataPartition(AppWindow* appWindow);
+    ~ScenarioCustomDataPartition() override;
+    static LRESULT CALLBACK ChildWndProcStatic(
+        HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
+
+private:
+    AppWindow* m_appWindow = nullptr;
+    wil::com_ptr<ICoreWebView2> m_webView;
+    std::wstring m_sampleUri;
+    EventRegistrationToken m_contentLoadingToken = {};
+    EventRegistrationToken m_webMessageReceivedToken = {};
+    EventRegistrationToken m_newWindowRequestedToken = {};
+    EventRegistrationToken m_childWebMessageReceivedToken = {};
+
+    // Track a single child popup window for partition management
+    HWND m_childWindow = nullptr;
+    wil::com_ptr<ICoreWebView2Controller> m_childController;
+    wil::com_ptr<ICoreWebView2> m_childWebView;
+
+    // Event handlers
+    LRESULT ChildWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
+    static bool EnsureChildWindowClassRegistered();
+    void CloseChildWindow();
+    void ResizeChildWebView();
+
+    void RegisterEventHandlers();
+    void HandleWebMessage(const std::wstring& message);
+    void SetPartitionOnLastChild(const std::wstring& partitionId);
+    void CheckCurrentPartition();
+    void SendStatusToUI(const std::wstring& status);
+    void SendStatusToChildUI(const std::wstring& status);
+};
diff --git a/SampleApps/WebView2APISample/WebView2APISample.rc b/SampleApps/WebView2APISample/WebView2APISample.rc
index 5904d534..4ce69982 100644
--- a/SampleApps/WebView2APISample/WebView2APISample.rc
+++ b/SampleApps/WebView2APISample/WebView2APISample.rc
@@ -274,6 +274,7 @@ BEGIN
             MENUITEM "Shared worker WebResourceRequested",   IDM_SCENARIO_SHARED_WORKER
         END
         MENUITEM "WebRTC UDP Port Configuration", IDM_SCENARIO_WEBRTC_UDP_PORT_CONFIGURATION
+        MENUITEM "Custom Data Partition for Child Windows", IDM_SCENARIO_CUSTOM_DATA_PARTITION
         POPUP "Custom Download Experience"
         BEGIN
             MENUITEM "Use Deferred Download Dialog",  IDM_SCENARIO_USE_DEFERRED_DOWNLOAD
diff --git a/SampleApps/WebView2APISample/WebView2APISample.vcxproj b/SampleApps/WebView2APISample/WebView2APISample.vcxproj
index ec3c5d66..a4dfe8ab 100644
--- a/SampleApps/WebView2APISample/WebView2APISample.vcxproj
+++ b/SampleApps/WebView2APISample/WebView2APISample.vcxproj
@@ -231,6 +231,7 @@
     <ClInclude Include="ScenarioAuthentication.h" />
     <ClInclude Include="ScenarioClientCertificateRequested.h" />
     <ClInclude Include="ScenarioCookieManagement.h" />
+    <ClInclude Include="ScenarioCustomDataPartition.h" />
     <ClInclude Include="ScenarioCustomDownloadExperience.h" />
     <ClInclude Include="ScenarioCustomScheme.h" />
     <ClInclude Include="ScenarioCustomSchemeNavigate.h" />
@@ -295,6 +296,7 @@
     <ClCompile Include="ScenarioAuthentication.cpp" />
     <ClCompile Include="ScenarioClientCertificateRequested.cpp" />
     <ClCompile Include="ScenarioCookieManagement.cpp" />
+    <ClCompile Include="ScenarioCustomDataPartition.cpp" />
     <ClCompile Include="ScenarioCustomDownloadExperience.cpp" />
     <ClCompile Include="ScenarioCustomScheme.cpp" />
     <ClCompile Include="ScenarioCustomSchemeNavigate.cpp" />
@@ -380,6 +382,15 @@
     <CopyFileToFolders Include="assets/ScenarioAcceleratorKeyPressed.html">
       <DestinationFolders>$(OutDir)\assets</DestinationFolders>
     </CopyFileToFolders>
+    <CopyFileToFolders Include="assets/ScenarioCustomDataPartition.html">
+      <DestinationFolders>$(OutDir)\assets</DestinationFolders>
+    </CopyFileToFolders>
+    <CopyFileToFolders Include="assets/ScenarioCustomDataPartitionChild.html">
+      <DestinationFolders>$(OutDir)\assets</DestinationFolders>
+    </CopyFileToFolders>
+    <CopyFileToFolders Include="assets/Sir_CV_Raman.JPG">
+      <DestinationFolders>$(OutDir)\assets</DestinationFolders>
+    </CopyFileToFolders>
     <CopyFileToFolders Include="assets/ScenarioCustomScheme.html">
       <DestinationFolders>$(OutDir)\assets</DestinationFolders>
     </CopyFileToFolders>
diff --git a/SampleApps/WebView2APISample/assets/ScenarioCustomDataPartition.html b/SampleApps/WebView2APISample/assets/ScenarioCustomDataPartition.html
new file mode 100644
index 00000000..4a324d0a
--- /dev/null
+++ b/SampleApps/WebView2APISample/assets/ScenarioCustomDataPartition.html
@@ -0,0 +1,251 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Custom Data Partition Sample</title>
+    <style>
+        body {
+            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
+            padding: 20px;
+            max-width: 800px;
+            margin: 0 auto;
+        }
+        h1 {
+            color: #0078d4;
+            border-bottom: 2px solid #0078d4;
+            padding-bottom: 10px;
+        }
+        .section {
+            margin: 20px 0;
+            padding: 15px;
+            border: 1px solid #ddd;
+            border-radius: 5px;
+            background-color: #f9f9f9;
+        }
+        .section h2 {
+            margin-top: 0;
+            color: #333;
+            font-size: 1.2em;
+        }
+        button {
+            background-color: #0078d4;
+            color: white;
+            border: none;
+            padding: 10px 20px;
+            font-size: 14px;
+            border-radius: 3px;
+            cursor: pointer;
+            margin: 5px;
+        }
+        button:hover {
+            background-color: #005a9e;
+        }
+        button:active {
+            background-color: #004578;
+        }
+        input[type="text"] {
+            padding: 8px;
+            font-size: 14px;
+            border: 1px solid #ccc;
+            border-radius: 3px;
+            width: 250px;
+            margin: 5px;
+        }
+        #statusArea {
+            margin-top: 15px;
+            padding: 10px;
+            background-color: #e7f3ff;
+            border: 1px solid #0078d4;
+            border-radius: 3px;
+            min-height: 30px;
+            font-size: 14px;
+        }
+        #testImage {
+            max-width: 200px;
+            border: 2px solid #0078d4;
+            border-radius: 5px;
+            margin: 10px 0;
+        }
+        .info-box {
+            background-color: #fff4ce;
+            border: 1px solid #ffb900;
+            border-radius: 3px;
+            padding: 10px;
+            margin: 10px 0;
+            font-size: 13px;
+        }
+        .blob-url {
+            font-family: 'Courier New', monospace;
+            font-size: 12px;
+            background-color: #f0f0f0;
+            padding: 5px;
+            border-radius: 3px;
+            word-break: break-all;
+            margin: 10px 0;
+        }
+    </style>
+</head>
+<body>
+    <h1>Custom Data Partition Sample</h1>
+
+    <div class="info-box">
+        <strong>About this sample:</strong> This demonstrates how to create child windows and apply custom data partitions
+        to isolate storage. It also tests blob URL sharing across partition boundaries.
+    </div>
+
+    <!-- Child Window Creation Section -->
+    <div class="section">
+        <h2>1. Create Child Window</h2>
+        <p>Click the button to open the child page. The parent window captures it via the NewWindowRequested event.</p>
+        <button onclick="createChildWindow()">Create Child Window</button>
+    </div>
+
+    <!-- Partition Management Section -->
+    <div class="section">
+        <h2>2. Set Custom Data Partition</h2>
+        <p>Enter a partition ID and apply it to the most recently created child window. The parent window will never have a custom partition.</p>
+        <input type="text" id="partitionInput" placeholder="Enter partition ID (e.g., 'partition-1')" value="my-partition">
+        <button onclick="setPartition()">Set Partition on Child Window</button>
+        <button onclick="checkPartition()">Check Parent Window Partition</button>
+        <button onclick="getMainWindowStoragePartition()">Get Main Window Storage Partition</button>
+        <div class="info-box" style="margin-top: 10px;">
+            <strong>Note:</strong> Only child windows should have custom partitions. The parent window remains in the default partition.
+            Click "Check Parent Window Partition" to verify the parent window has no custom partition set.
+        </div>
+    </div>
+
+    <!-- Blob URL Section -->
+    <div class="section">
+        <h2>3. Blob URL Creation & Testing</h2>
+        <p>This image is displayed in the parent window from assets. A blob URL will be created from it.</p>
+        <img id="testImage" src="Sir_CV_Raman.JPG" alt="Sir C V Raman">
+
+        <button onclick="createBlobUrl()">Create Blob URL</button>
+        <button onclick="testBlobUrlInChildWindow()">Test Blob URL in Child Window</button>
+
+        <div id="blobUrlDisplay" class="blob-url" style="display: none;">
+            <strong>Blob URL:</strong> <span id="blobUrlText"></span>
+        </div>
+
+        <div class="info-box" style="margin-top: 10px;">
+            <strong>Test:</strong> Create a blob URL from the image, then try to access it from a partitioned child window
+            to observe cross-partition behavior.
+        </div>
+    </div>
+
+    <!-- Status Area -->
+    <div class="section">
+        <h2>Status</h2>
+        <div id="statusArea">Ready. Click "Create Child Window" to begin.</div>
+    </div>
+
+    <script>
+        let currentBlobUrl = null;
+        let childWindowRef = null;
+
+        // Create a child window
+        function createChildWindow() {
+            const childUrl = 'https://appassets.example/ScenarioCustomDataPartitionChild.html?v=' + Date.now();
+            childWindowRef = window.open(childUrl, '_blank', 'width=600,height=800');
+            if (childWindowRef) {
+                updateStatus('Child window opened. You can now set partition on the captured child WebView.');
+            } else {
+                updateStatus('Error: Failed to open child window. Check popup settings.');
+            }
+        }
+
+        // Set partition on the last child window
+        function setPartition() {
+            const partitionId = document.getElementById('partitionInput').value.trim();
+            if (!partitionId) {
+                updateStatus('Error: Please enter a partition ID.');
+                return;
+            }
+
+            // Send message to C++ with partition ID
+            window.chrome.webview.postMessage('setPartition:' + partitionId);
+            updateStatus('Setting partition "' + partitionId + '" on child window...');
+        }
+
+        // Check the parent window's partition (should be default/none)
+        function checkPartition() {
+            window.chrome.webview.postMessage('checkPartition');
+            updateStatus('Checking parent window partition status...');
+        }
+
+        function getMainWindowStoragePartition() {
+            window.chrome.webview.postMessage('checkPartition');
+            updateStatus('Getting main window storage partition...');
+        }
+
+        window.addEventListener('message', function(event) {
+            if (!event.data || event.data.type !== 'getMainWindowStoragePartition') {
+                return;
+            }
+
+            getMainWindowStoragePartition();
+        });
+
+        // Create a blob URL from the test image
+        function createBlobUrl() {
+            fetch('Sir_CV_Raman.JPG')
+                .then(function(response) {
+                    if (!response.ok) {
+                        throw new Error('Failed to fetch Sir_CV_Raman.JPG');
+                    }
+                    return response.blob();
+                })
+                .then(function(blob) {
+                    if (currentBlobUrl) {
+                        URL.revokeObjectURL(currentBlobUrl);
+                    }
+
+                    currentBlobUrl = URL.createObjectURL(blob);
+                    document.getElementById('blobUrlText').textContent = currentBlobUrl;
+                    document.getElementById('blobUrlDisplay').style.display = 'block';
+
+                    updateStatus('Blob URL created successfully: ' + currentBlobUrl);
+                })
+                .catch(function(error) {
+                    updateStatus('Error creating blob URL: ' + error.message);
+                });
+        }
+
+        // Test blob URL accessibility from child window
+        function testBlobUrlInChildWindow() {
+            if (!currentBlobUrl) {
+                updateStatus('Error: Create a blob URL first before testing.');
+                return;
+            }
+
+            // Open a new window and try to load the blob URL
+            const testWindow = window.open('', '_blank', 'width=400,height=400');
+            if (testWindow) {
+                testWindow.document.write('<html><head><title>Blob URL Test</title></head><body style="font-family: Arial; padding: 20px;">');
+                testWindow.document.write('<h2>Testing Blob URL Access</h2>');
+                testWindow.document.write('<p>Attempting to load blob URL from parent window:</p>');
+                testWindow.document.write('<p style="font-family: monospace; font-size: 12px; word-break: break-all; background: #f0f0f0; padding: 10px;">' + currentBlobUrl + '</p>');
+                testWindow.document.write('<img src="' + currentBlobUrl + '" alt="Blob URL Image" style="max-width: 100%; border: 2px solid #0078d4;" onload="document.getElementById(\'result\').innerHTML=\'<span style=color:green>✓ Success: Blob URL accessible across partition!</span>\'" onerror="document.getElementById(\'result\').innerHTML=\'<span style=color:red>✗ Failed: Blob URL blocked by partition boundary</span>\'">');
+                testWindow.document.write('<div id="result" style="margin-top: 20px; font-weight: bold;"></div>');
+                testWindow.document.write('</body></html>');
+                testWindow.document.close();
+
+                updateStatus('Opened test window with blob URL. Check the new window for results.');
+            } else {
+                updateStatus('Error: Failed to open test window. Check popup settings.');
+            }
+        }
+
+        // Update status display (called from C++)
+        function updateStatus(message) {
+            document.getElementById('statusArea').textContent = message;
+        }
+
+        // Initialize
+        window.addEventListener('load', function() {
+            updateStatus('Sample loaded. Ready to demonstrate custom data partitions.');
+        });
+    </script>
+</body>
+</html>
diff --git a/SampleApps/WebView2APISample/assets/ScenarioCustomDataPartitionChild.html b/SampleApps/WebView2APISample/assets/ScenarioCustomDataPartitionChild.html
new file mode 100644
index 00000000..363de464
--- /dev/null
+++ b/SampleApps/WebView2APISample/assets/ScenarioCustomDataPartitionChild.html
@@ -0,0 +1,208 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Custom Data Partition Child Window</title>
+    <style>
+        body {
+            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
+            padding: 20px;
+            margin: 0;
+            color: #333;
+            background-color: #f9f9f9;
+        }
+        h1 {
+            color: #0078d4;
+            margin-top: 0;
+            border-bottom: 2px solid #0078d4;
+            padding-bottom: 10px;
+            font-size: 1.4em;
+        }
+        .section {
+            margin: 16px 0;
+            padding: 14px;
+            border: 1px solid #ddd;
+            border-radius: 5px;
+            background: #fff;
+        }
+        .hint {
+            background-color: #e7f3ff;
+            border: 1px solid #0078d4;
+            border-radius: 3px;
+            padding: 10px;
+            font-size: 13px;
+        }
+        .row {
+            display: flex;
+            gap: 8px;
+            margin-top: 8px;
+        }
+        input[type="text"] {
+            flex: 1;
+            padding: 8px;
+            font-size: 14px;
+            border: 1px solid #ccc;
+            border-radius: 3px;
+        }
+        button {
+            background-color: #0078d4;
+            color: white;
+            border: none;
+            padding: 8px 14px;
+            font-size: 14px;
+            border-radius: 3px;
+            cursor: pointer;
+        }
+        button:hover {
+            background-color: #005a9e;
+        }
+        button:active {
+            background-color: #004578;
+        }
+        #blobStatus {
+            margin-top: 10px;
+            font-size: 13px;
+        }
+        #childPartitionStatus {
+            margin-top: 10px;
+            font-size: 13px;
+        }
+        #localStorageStatus {
+            margin-top: 10px;
+            font-size: 13px;
+        }
+        #blobImage {
+            margin-top: 12px;
+            max-width: 100%;
+            border: 2px solid #0078d4;
+            border-radius: 5px;
+            display: none;
+        }
+    </style>
+</head>
+<body>
+    <h1>Custom Data Partition Child Window</h1>
+
+    <div class="section">
+        <p>This is the dedicated child window page opened by <strong>window.open()</strong> from the parent scenario page.</p>
+        <p>The parent app captures this window in <strong>NewWindowRequested</strong>, then you can apply a custom partition from the parent UI.</p>
+    </div>
+
+    <div class="hint">
+        Keep this child window open while setting partition IDs in the parent window.
+    </div>
+
+    <div class="section">
+        <h2>Blob URL Image Test</h2>
+        <p>Paste a blob URL from the parent window and try loading it here.</p>
+        <label for="blobUrlInput">Blob URL</label>
+        <form class="row" onsubmit="event.preventDefault(); loadBlobUrlImage();">
+            <input type="text" id="blobUrlInput" placeholder="Paste blob URL here">
+            <button type="submit">Load Image</button>
+            <button type="button" onclick="clearBlobUrlImage()">Clear Image</button>
+        </form>
+        <div id="blobStatus">Waiting for blob URL input.</div>
+        <img id="blobImage" alt="Blob URL image preview">
+    </div>
+
+    <div class="section">
+        <h2>Custom Partition</h2>
+        <p>Query the child window's current custom data partition from native code.</p>
+        <button type="button" onclick="getCustomPartition()">Get Custom Partition</button>
+        <button type="button" onclick="requestMainWindowPartition()">Get Main Window Storage Partition</button>
+        <div id="childPartitionStatus">Waiting to query partition.</div>
+    </div>
+
+    <div class="section">
+        <h2>Local Storage Test</h2>
+        <p>Use key <strong>currentTime</strong> to verify storage behavior across partitions.</p>
+        <button type="button" onclick="setCurrentTimeInStorage()">Set currentTime</button>
+        <button type="button" onclick="readCurrentTimeFromStorage()">Read currentTime</button>
+        <div id="localStorageStatus">Waiting to test local storage.</div>
+    </div>
+
+    <script>
+        function loadBlobUrlImage() {
+            const input = document.getElementById('blobUrlInput');
+            const status = document.getElementById('blobStatus');
+            const image = document.getElementById('blobImage');
+            const blobUrl = input.value.trim();
+
+            if (!blobUrl) {
+                status.textContent = 'Error: Please paste a blob URL first.';
+                image.style.display = 'none';
+                image.removeAttribute('src');
+                return;
+            }
+
+            status.textContent = 'Loading image from blob URL...';
+            image.style.display = 'none';
+
+            image.onload = function() {
+                status.textContent = '✓ Image loaded successfully from blob URL.';
+                image.style.display = 'block';
+            };
+
+            image.onerror = function() {
+                status.textContent = '✗ Failed to load image from blob URL (possible partition boundary).';
+                image.style.display = 'none';
+            };
+
+            image.src = blobUrl;
+        }
+
+        function clearBlobUrlImage() {
+            const input = document.getElementById('blobUrlInput');
+            const status = document.getElementById('blobStatus');
+            const image = document.getElementById('blobImage');
+
+            input.value = '';
+            image.style.display = 'none';
+            image.removeAttribute('src');
+            status.textContent = 'Image cleared. Waiting for blob URL input.';
+        }
+
+        function getCustomPartition() {
+            if (window.chrome && window.chrome.webview) {
+                window.chrome.webview.postMessage('getCustomPartition');
+                updateChildPartitionStatus('Querying child custom partition...');
+            } else {
+                updateChildPartitionStatus('Error: WebView bridge unavailable in this context.');
+            }
+        }
+
+        function updateChildPartitionStatus(message) {
+            document.getElementById('childPartitionStatus').textContent = message;
+        }
+
+        function requestMainWindowPartition() {
+            if (!window.opener || window.opener.closed) {
+                updateChildPartitionStatus('Error: Main window is not available.');
+                return;
+            }
+
+            window.opener.postMessage({ type: 'getMainWindowStoragePartition' }, '*');
+            updateChildPartitionStatus('Requested main window storage partition. Check parent status area.');
+        }
+
+        function setCurrentTimeInStorage() {
+            const now = new Date().toISOString();
+            localStorage.setItem('currentTime', now);
+            document.getElementById('localStorageStatus').textContent =
+                'Stored currentTime: ' + now;
+        }
+
+        function readCurrentTimeFromStorage() {
+            const value = localStorage.getItem('currentTime');
+            if (value) {
+                document.getElementById('localStorageStatus').textContent =
+                    'Read currentTime: ' + value;
+            } else {
+                document.getElementById('localStorageStatus').textContent =
+                    'No currentTime found in localStorage for this partition.';
+            }
+        }
+    </script>
+</body>
+</html>
diff --git a/SampleApps/WebView2APISample/assets/Sir_CV_Raman.JPG b/SampleApps/WebView2APISample/assets/Sir_CV_Raman.JPG
new file mode 100644
index 00000000..5c302e8c
Binary files /dev/null and b/SampleApps/WebView2APISample/assets/Sir_CV_Raman.JPG differ
diff --git a/SampleApps/WebView2APISample/resource.h b/SampleApps/WebView2APISample/resource.h
index d2474cdc..efdeffbd 100644
--- a/SampleApps/WebView2APISample/resource.h
+++ b/SampleApps/WebView2APISample/resource.h
@@ -221,6 +221,7 @@
 #define IDM_SCENARIO_DEDICATED_WORKER_POST_MESSAGE 3009
 #define IDM_SCENARIO_SERVICE_WORKER_POST_MESSAGE 3010
 #define IDM_SCENARIO_WEBRTC_UDP_PORT_CONFIGURATION 3011
+#define IDM_SCENARIO_CUSTOM_DATA_PARTITION 3012
 #define ID_BLOCKEDSITES                 32773
 #define ID_SETTINGS_NAVIGATETOSTRING    32774
 #define ID_ADD_INITIALIZE_SCRIPT        32775
diff --git a/SampleApps/WebView2Samples.sln b/SampleApps/WebView2Samples.sln
index 9ff80692..942f38e2 100644
--- a/SampleApps/WebView2Samples.sln
+++ b/SampleApps/WebView2Samples.sln
@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
-VisualStudioVersion = 16.0.30011.22
+# Visual Studio Version 17
+VisualStudioVersion = 17.14.36915.13 d17.14
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "WebView2APISample", "WebView2APISample\WebView2APISample.vcxproj", "{4F0CEEF3-12B3-425E-9BB0-105200411592}"
 EndProject