diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Pages/SenderPage.razor b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Pages/SenderPage.razor
index 1332b47b..b154cbc6 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Pages/SenderPage.razor
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Pages/SenderPage.razor
@@ -113,12 +113,12 @@
                     }
                 </button>
 
-                <button class="sender-btn" @onclick="ShowPreview" disabled="@(_selectedEnvelope == null)" title="@L("Sender_Preview_Title", "Ausgewählten Umschlag als PDF anzeigen")">
+                <button class="sender-btn" @onclick="ShowPreview" disabled="@(_selectedEnvelope == null)" title="@L("Sender_ShowOriginalDocument_Title", "Originaldokument anzeigen")">
                     <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" fill="currentColor" viewBox="0 0 16 16">
                         <path d="M10.5 8a2.5 2.5 0 1 1-5 0 2.5 2.5 0 0 1 5 0z"/>
                         <path d="M0 8s3-5.5 8-5.5S16 8 16 8s-3 5.5-8 5.5S0 8 0 8zm8 3.5a3.5 3.5 0 1 0 0-7 3.5 3.5 0 0 0 0 7z"/>
                     </svg>
-                    @L("Preview", "Vorschau")
+                    @L("Sender_ShowOriginalDocument", "Original Dokument anzeigen")
                 </button>
 
                 <div class="sender-export-group" title="@L("Sender_ExportView_Title", "Export der aktuellen Tabellenansicht")">
@@ -454,7 +454,7 @@
 
 @* ── PDF Vorschau Popup ────────────────────────────────────────────────── *@
 <DxPopup @bind-Visible="@_previewVisible"
-         HeaderText="@($"{(_activeTab == "completed" && _selectedEnvelope?.Status == EnvelopeStatus.EnvelopeCompletelySigned ? L("SignedPdf", "Signiertes PDF") : L("Preview", "Vorschau"))} — {_selectedEnvelope?.Title} (#{_selectedEnvelope?.Id})")"
+         HeaderText="@($"{(_activeTab == "completed" && _selectedEnvelope?.Status == EnvelopeStatus.EnvelopeCompletelySigned ? L("SignedPdf", "Signiertes PDF") : L("Sender_OriginalDocument", "Originaldokument"))} — {_selectedEnvelope?.Title} (#{_selectedEnvelope?.Id})")"
          Width="80vw"
          MaxWidth="80vw"
          Height="90vh"
@@ -503,6 +503,22 @@
         else if (_previewPdfBytes is not null && _previewViewerMounted)
         {
             <div class="sender-preview-viewer-wrap">
+                @if (_showPreviewHint)
+                {
+                    <div class="sender-preview-info" style="display:flex;align-items:center;justify-content:space-between;gap:0.5rem;padding:0.625rem 0.75rem;margin:0 0 0.5rem 0;background:#eff6ff;border:1px solid #bfdbfe;border-radius:8px;color:#1e3a8a;font-size:0.85rem;">
+                        <span>@L("Sender_OriginalDocument_NoSignatureFieldsHint", "Hinweis: In dieser Ansicht werden keine Unterschriftsfelder angezeigt.")</span>
+                        <button type="button"
+                                class="sender-preview-info__close"
+                                @onclick="DismissPreviewHint"
+                                title="@L("Close", "Schliessen")"
+                                aria-label="@L("Close", "Schliessen")"
+                                style="display:inline-flex;align-items:center;justify-content:center;padding:0.125rem;border:none;background:transparent;box-shadow:none;appearance:none;cursor:pointer;color:#1e3a8a;line-height:1;">
+                            <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" fill="currentColor" viewBox="0 0 16 16" aria-hidden="true" focusable="false">
+                                <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.75.75 0 1 1 1.06 1.06L9.06 8l3.22 3.22a.75.75 0 1 1-1.06 1.06L8 9.06l-3.22 3.22a.75.75 0 1 1-1.06-1.06L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06z"/>
+                            </svg>
+                        </button>
+                    </div>
+                }
                 <SenderPdfImageEditor IsPlacementMode="false"
                                       PageCount="@_previewPageCount"
                                       Pages="@_previewPagePreviews"
@@ -591,6 +607,9 @@
     private string _previewFileName = "document.pdf";
     private string? _previewErrorMessage = null;
     private readonly IReadOnlyList<SenderPdfFieldOverlay> _previewFieldOverlays = [];
+    private bool _showPreviewHint = false;
+    private int _previewHintVersion = 0;
+    private const int PreviewHintAutoHideMs = 4000;
 
     private string? PreviewPdfDataUrl => _previewPdfBytes is { Length: > 0 }
         ? $"data:application/pdf;base64,{Convert.ToBase64String(_previewPdfBytes)}"
@@ -1165,6 +1184,7 @@
 
             // PDF ready — mount the viewer now
             _previewViewerMounted = true;
+            ShowPreviewHint();
         }
         catch (HttpRequestException ex) when ((int?)ex.StatusCode == 404)
         {
@@ -1189,6 +1209,9 @@
 
     void OnPreviewClosed()
     {
+        _previewHintVersion++;
+        _showPreviewHint = false;
+
         // Unmount the viewer first — prevent DevExpress async render from
         // accessing the already-disposed byte array
         _previewViewerMounted = false;
@@ -1220,6 +1243,28 @@
         return Task.CompletedTask;
     }
 
+    void DismissPreviewHint()
+    {
+        _previewHintVersion++;
+        _showPreviewHint = false;
+    }
+
+    void ShowPreviewHint()
+    {
+        _showPreviewHint = true;
+        var currentVersion = ++_previewHintVersion;
+
+        _ = Task.Run(async () =>
+        {
+            await Task.Delay(PreviewHintAutoHideMs);
+            if (currentVersion != _previewHintVersion)
+                return;
+
+            _showPreviewHint = false;
+            await InvokeAsync(StateHasChanged);
+        });
+    }
+
     static int? EstimatePdfPageCount(byte[]? documentBytes)
     {
         if (documentBytes is null || documentBytes.Length == 0)