Index: src/routes/admin-sites.js
===================================================================
--- src/routes/admin-sites.js	(revision 662345333cce064d12731d86e9a2ede2f4b6805c)
+++ src/routes/admin-sites.js	(revision 8f6225cbfb7a439454829f7dec26b0891f4163f0)
@@ -25,4 +25,5 @@
 import ThemeService from '../services/ThemeService.js';
 import { listPlatforms, PLATFORMS } from '../services/PlatformIcons.js';
+import { toWebp } from '../services/ImageWebpService.js';
 
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
@@ -88,5 +89,5 @@
     res.json({
       ok: true,
-      url: `/media/avatars/${req.file.filename}`,
+      url: `/media/avatars/${toWebp(req.file)}`,
       size: req.file.size,
       mime: req.file.mimetype,