diff --git a/webui/backend/tests/golden/__pycache__/test_ui_smoke_golden.cpython-313.pyc b/webui/backend/tests/golden/__pycache__/test_ui_smoke_golden.cpython-313.pyc
index 387bf88..d924355 100644
Binary files a/webui/backend/tests/golden/__pycache__/test_ui_smoke_golden.cpython-313.pyc and b/webui/backend/tests/golden/__pycache__/test_ui_smoke_golden.cpython-313.pyc differ
diff --git a/webui/backend/tests/golden/test_ui_smoke_golden.py b/webui/backend/tests/golden/test_ui_smoke_golden.py
index bd7f840..58fa5d5 100644
--- a/webui/backend/tests/golden/test_ui_smoke_golden.py
+++ b/webui/backend/tests/golden/test_ui_smoke_golden.py
@@ -200,7 +200,12 @@ class UiSmokeGoldenTest(unittest.TestCase):
         self.assertIn('function imageElements()', app_js)
         self.assertIn('function isImageSelection(item)', app_js)
         self.assertIn('async function openImageViewer()', app_js)
+        self.assertIn('if (isImageSelection(item)) {', app_js)
+        self.assertIn('openImageViewer();', app_js)
         self.assertIn('function isImageOpen()', app_js)
+        self.assertIn('requestAnimationFrame(() => {', app_js)
+        self.assertIn('if (!fitImageToViewport()) {', app_js)
+        self.assertIn('if (!viewport.clientWidth || !viewport.clientHeight) {', app_js)
         self.assertIn("`/api/files/image?", app_js)
         self.assertIn('if (isImageSelection(selected)) {', app_js)
         self.assertIn('document.getElementById("info-modal")', app_js)
diff --git a/webui/html/app.js b/webui/html/app.js
index 1fc8e6a..8e1ac4a 100644
--- a/webui/html/app.js
+++ b/webui/html/app.js
@@ -1009,7 +1009,16 @@ function renderPaneItems(pane) {
       }
       renderPaneItems(pane);
     };
-    if (entry.kind === "file" && isVideoSelection({ path: entry.path, name: entry.name, kind: entry.kind })) {
+    if (entry.kind === "file" && isImageSelection({ path: entry.path, name: entry.name, kind: entry.kind })) {
+      row.ondblclick = (ev) => {
+        ev.stopPropagation();
+        setActivePane(pane);
+        model.currentRowIndex = index;
+        setSingleSelectionAtIndex(pane, { path: entry.path, name: entry.name, kind: entry.kind }, index);
+        renderPaneItems(pane);
+        openImageViewer();
+      };
+    } else if (entry.kind === "file" && isVideoSelection({ path: entry.path, name: entry.name, kind: entry.kind })) {
       row.ondblclick = (ev) => {
         ev.stopPropagation();
         setActivePane(pane);
@@ -1827,13 +1836,21 @@ function fitImageToViewport() {
   const image = imageElements().image;
   const viewport = imageElements().viewport;
   if (!image.naturalWidth || !image.naturalHeight) {
-    return;
+    return false;
+  }
+  if (!viewport.clientWidth || !viewport.clientHeight) {
+    return false;
   }
   const widthScale = viewport.clientWidth / image.naturalWidth;
   const heightScale = viewport.clientHeight / image.naturalHeight;
-  imageViewerState.fitScale = Math.min(widthScale, heightScale, 1);
+  const fitScale = Math.min(widthScale, heightScale, 1);
+  if (!Number.isFinite(fitScale) || fitScale <= 0) {
+    return false;
+  }
+  imageViewerState.fitScale = fitScale;
   imageViewerState.scale = imageViewerState.fitScale;
   applyImageScale();
+  return true;
 }
 
 function adjustImageZoom(multiplier) {
@@ -2232,7 +2249,13 @@ async function openImageViewer() {
   image.error.textContent = "";
   image.image.alt = selected.name;
   image.image.onload = () => {
-    fitImageToViewport();
+    requestAnimationFrame(() => {
+      if (!fitImageToViewport()) {
+        requestAnimationFrame(() => {
+          fitImageToViewport();
+        });
+      }
+    });
     image.image.onload = null;
   };
   image.image.onerror = () => {
@@ -2405,6 +2428,10 @@ function openCurrentDirectory() {
     navigateTo(pane, item.path);
     return;
   }
+  if (isImageSelection(item)) {
+    openImageViewer();
+    return;
+  }
   if (isVideoSelection(item)) {
     openVideoViewer();
   }