diff --git a/InteractiveHtmlBom/web/ibom.css b/InteractiveHtmlBom/web/ibom.css
index cbd0e38..1bc0d3a 100644
--- a/InteractiveHtmlBom/web/ibom.css
+++ b/InteractiveHtmlBom/web/ibom.css
@@ -603,6 +603,15 @@ mark.highlight {
   border-top: 1px solid #ccc;
 }
 
+.menu-warning {
+  margin: 5px 5px 0 5px;
+  color: #c00;
+}
+
+.dark .menu-warning {
+  color: #f66;
+}
+
 .menu-textbox {
   float: left;
   height: 24px;
diff --git a/InteractiveHtmlBom/web/ibom.html b/InteractiveHtmlBom/web/ibom.html
index a6e5a6d..3a71bdc 100644
--- a/InteractiveHtmlBom/web/ibom.html
+++ b/InteractiveHtmlBom/web/ibom.html
@@ -280,6 +280,7 @@
               <button class="savebtn" onclick="saveBomTable('csv')">csv</button>
               <button class="savebtn" onclick="saveBomTable('txt')">txt</button>
             </div>
+            <div id="bom-filter-warning" class="menu-warning" style="display: none"></div>
           </div>
         </div>
       </div>
diff --git a/InteractiveHtmlBom/web/ibom.js b/InteractiveHtmlBom/web/ibom.js
index d88a6f8..3c69b02 100644
--- a/InteractiveHtmlBom/web/ibom.js
+++ b/InteractiveHtmlBom/web/ibom.js
@@ -821,9 +821,29 @@ function highlightNextRow() {
   smoothScrollToRow(currentHighlightedRowId);
 }
 
+function updateBomFilterWarning() {
+  var reasons = [];
+  var front = settings.canvaslayout == "F";
+  // Only warn about the side when the other side has components
+  if (settings.bommode != "netlist" && settings.canvaslayout != "FB" &&
+    pcbdata.bom[front ? "B" : "F"].length > 0) {
+    reasons.push(front ? "front side only" : "back side only");
+  }
+  if (filter) {
+    reasons.push("filter");
+  }
+  if (reflookup && settings.bommode != "netlist") {
+    reasons.push("ref lookup");
+  }
+  var warning = document.getElementById("bom-filter-warning");
+  warning.textContent = "Table is filtered (" + reasons.join(", ") + "), saved file will not contain all rows";
+  warning.style.display = reasons.length ? "" : "none";
+}
+
 function populateBomTable() {
   populateBomHeader();
   populateBomBody();
+  updateBomFilterWarning();
   setBomHandlers();
   resizableGrid(bomhead);
 }