diff --git a/apps/desktop/src/components/AttachmentImage.tsx b/apps/desktop/src/components/AttachmentImage.tsx
index 6f3400c..ded19e0 100644
--- a/apps/desktop/src/components/AttachmentImage.tsx
+++ b/apps/desktop/src/components/AttachmentImage.tsx
@@ -3,7 +3,8 @@ import { useEffect, useState } from 'react';
 
 import { getCachedAttachment, putCachedAttachment } from '../lib/attachmentCache';
 import { supabase } from '../lib/supabase';
-import { AlertIcon, SpinnerIcon, XIcon } from './icons';
+import { AlertIcon, SpinnerIcon } from './icons';
+import { Lightbox } from './Lightbox';
 
 interface Props {
   handle: AttachmentHandle;
@@ -136,42 +137,5 @@ export function AttachmentImage({ handle }: Props) {
   );
 }
 
-function Lightbox({ url, onClose }: { url: string; onClose: () => void }) {
-  useEffect(() => {
-    function onKey(e: KeyboardEvent) {
-      if (e.key === 'Escape') onClose();
-    }
-    document.addEventListener('keydown', onKey);
-    const prevOverflow = document.body.style.overflow;
-    document.body.style.overflow = 'hidden';
-    return () => {
-      document.removeEventListener('keydown', onKey);
-      document.body.style.overflow = prevOverflow;
-    };
-  }, [onClose]);
-
-  return (
-    <div
-      role="dialog"
-      aria-modal="true"
-      aria-label="Bildansicht"
-      onClick={onClose}
-      className="fixed inset-0 z-50 flex items-center justify-center bg-ink-950/90 p-6 backdrop-blur-sm animate-fade-in"
-    >
-      <button
-        type="button"
-        onClick={onClose}
-        aria-label="Schließen"
-        className="absolute right-4 top-4 flex h-10 w-10 cursor-pointer items-center justify-center rounded-full border border-white/10 bg-ink-900/80 text-neutral-200 transition hover:bg-white/10 focus:outline-none focus-visible:ring-2 focus-visible:ring-brand-400/40"
-      >
-        <XIcon className="h-5 w-5" />
-      </button>
-      <img
-        src={url}
-        alt="attachment full"
-        onClick={(e) => e.stopPropagation()}
-        className="max-h-[92vh] max-w-[92vw] rounded-xl object-contain shadow-2xl"
-      />
-    </div>
-  );
-}
+// Lightbox extracted to ./Lightbox.tsx so the settings avatar preview and
+// any future surface can reuse the same dialog without duplication.
diff --git a/apps/desktop/src/components/Lightbox.tsx b/apps/desktop/src/components/Lightbox.tsx
new file mode 100644
index 0000000..9c7a07f
--- /dev/null
+++ b/apps/desktop/src/components/Lightbox.tsx
@@ -0,0 +1,51 @@
+import { useEffect } from 'react';
+
+import { XIcon } from './icons';
+
+// Fullscreen image viewer. Backdrop click + Esc close. Originally lived
+// inside AttachmentImage.tsx as a file-private component; extracted here
+// so other surfaces (settings avatar preview, future profile popover,
+// etc.) can reuse the exact same dialog without duplicating the chrome.
+//
+// The image itself stops click propagation so a click on the picture
+// keeps the lightbox open — only the backdrop or the explicit close
+// button dismisses.
+export function Lightbox({ url, onClose }: { url: string; onClose: () => void }) {
+  useEffect(() => {
+    function onKey(e: KeyboardEvent) {
+      if (e.key === 'Escape') onClose();
+    }
+    document.addEventListener('keydown', onKey);
+    const prevOverflow = document.body.style.overflow;
+    document.body.style.overflow = 'hidden';
+    return () => {
+      document.removeEventListener('keydown', onKey);
+      document.body.style.overflow = prevOverflow;
+    };
+  }, [onClose]);
+
+  return (
+    <div
+      role="dialog"
+      aria-modal="true"
+      aria-label="Bildansicht"
+      onClick={onClose}
+      className="fixed inset-0 z-50 flex items-center justify-center bg-ink-950/90 p-6 backdrop-blur-sm animate-fade-in"
+    >
+      <button
+        type="button"
+        onClick={onClose}
+        aria-label="Schließen"
+        className="absolute right-4 top-4 flex h-10 w-10 cursor-pointer items-center justify-center rounded-full border border-white/10 bg-ink-900/80 text-neutral-200 transition hover:bg-white/10 focus:outline-none focus-visible:ring-2 focus-visible:ring-brand-400/40"
+      >
+        <XIcon className="h-5 w-5" />
+      </button>
+      <img
+        src={url}
+        alt=""
+        onClick={(e) => e.stopPropagation()}
+        className="max-h-[92vh] max-w-[92vw] rounded-xl object-contain shadow-2xl"
+      />
+    </div>
+  );
+}
diff --git a/apps/desktop/src/pages/SettingsPage.tsx b/apps/desktop/src/pages/SettingsPage.tsx
index 22c173c..e951d52 100644
--- a/apps/desktop/src/pages/SettingsPage.tsx
+++ b/apps/desktop/src/pages/SettingsPage.tsx
@@ -33,6 +33,7 @@ import {
   uploadBannerBlob,
 } from '../lib/bannerUpload';
 import { ImageCropDialog } from '../components/ImageCropDialog';
+import { Lightbox } from '../components/Lightbox';
 import { devLocalSecretStore } from '../lib/secretStore';
 import {
   getPttSettings,
@@ -799,6 +800,9 @@ function ProfileVisualsControls({ patchProfile, busy }: AvatarControlsProps) {
   // ratios.
   const [cropFile, setCropFile] = useState<File | null>(null);
   const [cropKind, setCropKind] = useState<'avatar' | 'banner' | null>(null);
+  // Lightbox toggle for the avatar live-preview. Clicking the in-page
+  // avatar opens a fullscreen view; clicking outside / Esc dismisses.
+  const [avatarPreviewOpen, setAvatarPreviewOpen] = useState(false);
 
   const userId = profile?.userId;
   const avatarUrl = profile?.avatarUrl ?? null;
@@ -930,11 +934,33 @@ function ProfileVisualsControls({ patchProfile, busy }: AvatarControlsProps) {
           className="relative z-10 flex items-end gap-3 px-4 pb-3"
           style={{ marginTop: '-2rem' }}
         >
-          <Avatar
-            url={avatarUrl}
-            displayName={displayName}
-            className="h-16 w-16 rounded-full text-2xl ring-4 ring-surface-3"
-          />
+          <button
+            type="button"
+            onClick={() => {
+              if (avatarUrl) setAvatarPreviewOpen(true);
+            }}
+            // Disabled when there's no uploaded avatar — clicking the
+            // generated-initial placeholder would open an empty lightbox.
+            disabled={!avatarUrl}
+            aria-label={
+              avatarUrl
+                ? t('app:settings.avatar_preview', { defaultValue: 'Profilbild vergrößern' })
+                : undefined
+            }
+            // appearance-none + reset border/bg/padding so the native
+            // button chrome (outset border, button-face background, 1px
+            // padding) doesn't draw a box around the avatar circle.
+            className={
+              'appearance-none border-0 bg-transparent p-0 rounded-full focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40 ' +
+              (avatarUrl ? 'cursor-zoom-in' : 'cursor-default')
+            }
+          >
+            <Avatar
+              url={avatarUrl}
+              displayName={displayName}
+              className="h-16 w-16 rounded-full text-2xl ring-4 ring-surface-3"
+            />
+          </button>
           <div className="min-w-0 flex-1 pb-1">
             <div className="truncate text-sm font-semibold text-fg">
               {displayName ?? '—'}
@@ -1061,6 +1087,9 @@ function ProfileVisualsControls({ patchProfile, busy }: AvatarControlsProps) {
         }}
         onClose={closeCropDialog}
       />
+      {avatarPreviewOpen && avatarUrl && (
+        <Lightbox url={avatarUrl} onClose={() => setAvatarPreviewOpen(false)} />
+      )}
     </div>
   );
 }