diff --git a/.last-branch b/.last-branch
index 13abcc4..f412f8f 100644
--- a/.last-branch
+++ b/.last-branch
@@ -1 +1 @@
-v20260103-19-reports-output-format-html
+v20260103-20-reports-export-html-open-new-tab
diff --git a/containers/backupchecks/src/templates/main/reports.html b/containers/backupchecks/src/templates/main/reports.html
index 5c23126..3e0de3a 100644
--- a/containers/backupchecks/src/templates/main/reports.html
+++ b/containers/backupchecks/src/templates/main/reports.html
@@ -53,7 +53,7 @@
                       <a class="btn btn-sm btn-outline-secondary" href="{{ url_for('main.reports_edit', report_id=item.id) }}">Edit</a>
                       <button type="button" class="btn btn-sm btn-outline-primary rep-generate-btn" data-id="{{ item.id }}">Generate</button>
                       <button type="button" class="btn btn-sm btn-outline-secondary ms-1 rep-view-btn" data-id="{{ item.id }}">View raw</button>
-                      <a class="btn btn-sm btn-outline-success rep-download-btn ms-1" href="/api/reports/{{ item.id }}/export" target="_blank" rel="noopener">Download</a>
+                      <a class="btn btn-sm btn-outline-success rep-download-btn ms-1" href="/api/reports/{{ item.id }}/export?format={{ (item.output_format or 'csv')|lower }}" target="_blank" rel="noopener">Download</a>
                       {% if active_role in ('admin','operator','reporter') %}
                         <button type="button" class="btn btn-sm btn-outline-danger rep-delete-btn ms-1" data-id="{{ item.id }}">Delete</button>
                       {% endif %}
@@ -394,7 +394,7 @@ function loadRawData() {
             '<a class="btn btn-sm btn-outline-secondary me-1" href="/reports/' + item.id + '/edit">Edit</a>' +
             '<button type="button" class="btn btn-sm btn-outline-primary me-1 rep-generate-btn" data-id="' + item.id + '">Generate</button>' +
             '<button type="button" class="btn btn-sm btn-outline-secondary me-1 rep-view-btn" data-id="' + item.id + '">View raw</button>' +
-            '<a class="btn btn-sm btn-outline-success rep-download-btn" href="/api/reports/' + item.id + '/export" target="_blank" rel="noopener">Download</a>' +
+            '<a class="btn btn-sm btn-outline-success rep-download-btn" href="/api/reports/' + item.id + '/export?format=' + encodeURIComponent((item.output_format || 'csv').toLowerCase()) + '" target="_blank" rel="noopener">Download</a>' +
             (canDeleteReports ? '<button type="button" class="btn btn-sm btn-outline-danger ms-1 rep-delete-btn" data-id="' + item.id + '">Delete</button>' : '') +
           '</td>';;
 
diff --git a/docs/changelog.md b/docs/changelog.md
index 9a9b23a..f98f049 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -172,6 +172,14 @@
 - Updated the Reports overview to use the new generic export endpoint (no longer hardcoded to export.csv).
 - Added ReportLab dependency for PDF generation.
 
+---
+
+## v20260103-20-reports-export-html-open-new-tab
+
+- Fixed report export logic so the selected output format is always respected.
+- Ensured the export URL explicitly includes the chosen format parameter (CSV, PDF, HTML).
+- Changed HTML report handling to open in a new browser tab instead of triggering a file download.
+- Enabled proper inline rendering of HTML reports to support graphical preview and layout validation.
 
 ================================================================================================================================================