diff --git a/src/lib/components/ImageTile.svelte b/src/lib/components/ImageTile.svelte
index 3f8ac13..dfe8c74 100644
--- a/src/lib/components/ImageTile.svelte
+++ b/src/lib/components/ImageTile.svelte
@@ -12,16 +12,36 @@
   const placeholder = 'data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIxMDAlIiBoZWlnaHQ9IjEwMCUiPjxyZWN0IGZpbGw9IiMzMzMiIHdpZHRoPSIxMDAlIiBoZWlnaHQ9IjEwMCUiLz48L3N2Zz4=';
   
   let imageSrc = $derived(src || placeholder);
+
+  // Generate srcset for optimized images from our proxy
+  let srcset = $derived.by(() => {
+    if (!src || !src.startsWith('/assets/')) return undefined;
+    
+    const widths = [400, 800, 1200, 1600];
+    const sets = widths.map(w => `${src}${src.includes('?') ? '&' : '?'}w=${w} ${w}w`);
+    
+    // Add original as fallback
+    sets.push(`${src} 2000w`);
+    
+    return sets.join(', ');
+  });
+
+  const sizes = "(max-width: 640px) 100vw, (max-width: 1024px) 50vw, 33vw";
 </script>
 
 <div class="grid grid-cols-1 grid-rows-1">
   <img
     src={imageSrc}
+    {srcset}
+    {sizes}
     {alt}
+    loading="lazy"
     class="row-start-1 col-start-1 pointer-events-none w-full h-96 object-cover"
     onerror={(e) => {
       const img = e.currentTarget as HTMLImageElement;
       img.src = placeholder;
+      // Clear srcset on error to avoid loading broken thumbnails
+      img.srcset = "";
     }}
   />
   <div class="row-start-1 col-start-1">
diff --git a/src/lib/components/Markdown.svelte b/src/lib/components/Markdown.svelte
index d030734..f0e1fb5 100644
--- a/src/lib/components/Markdown.svelte
+++ b/src/lib/components/Markdown.svelte
@@ -21,8 +21,17 @@
         src = `${normalizedBasePath}/${href}`.replace(/\/+/g, '/');
       }
       src = `/assets${src}`;
+
+      // Generate srcset for optimized images
+      const widths = [400, 800, 1200, 1600, 2000];
+      const srcset = widths
+        .map(w => `${src}?w=${w} ${w}w`)
+        .join(', ');
+      const sizes = "(max-width: 1024px) 100vw, 1024px";
+
+      return `<img src="${src}" srcset="${srcset}" sizes="${sizes}" alt="${text}" title="${title || ''}" loading="lazy" />`;
     }
-    return `<img src="${src}" alt="${text}" title="${title || ''}" />`;
+    return `<img src="${src}" alt="${text}" title="${title || ''}" loading="lazy" />`;
   };
 
   let html = $derived(
diff --git a/src/lib/server/nextcloud.ts b/src/lib/server/nextcloud.ts
index 42490eb..6d80ce6 100644
--- a/src/lib/server/nextcloud.ts
+++ b/src/lib/server/nextcloud.ts
@@ -37,7 +37,6 @@ export async function getCoverImage(slug: string): Promise<string | null> {
   return withCache(`cover:${slug}`, async () => {
     try {
       const contents = await client.getDirectoryContents("/" + slug);
-      console.log(contents);
       if (!Array.isArray(contents)) return null;
 
       const cover = contents.find(
diff --git a/src/routes/assets/[...path]/+server.ts b/src/routes/assets/[...path]/+server.ts
index c08a4a2..5080a11 100644
--- a/src/routes/assets/[...path]/+server.ts
+++ b/src/routes/assets/[...path]/+server.ts
@@ -2,24 +2,80 @@ import { client } from "$lib/server/nextcloud";
 import { error } from "@sveltejs/kit";
 import type { RequestHandler } from "./$types";
 import mime from "mime-types";
+import { env } from "$env/dynamic/private";
 
-export const GET: RequestHandler = async ({ params }) => {
+export const GET: RequestHandler = async ({ params, url }) => {
     const { path } = params;
+    const width = url.searchParams.get("w");
+    const height = url.searchParams.get("h");
     
     if (!path) {
         throw error(400, "Path is required");
     }
 
     try {
-        // Fetch from Nextcloud. We assume the path is relative to the root or a specific folder.
-        // If your files are in a specific folder, e.g., "Schreifuchs", prepend it here.
-        const buffer = await client.getFileContents("/" + path);
-        const contentType = mime.lookup(path) || "application/octet-stream";
+        let buffer: ArrayBuffer;
+        let contentType: string;
+
+        if (width || height) {
+            // Use Nextcloud Preview API
+            const baseUrl = env.NEXTCLOUD_URL?.endsWith("/") ? env.NEXTCLOUD_URL : `${env.NEXTCLOUD_URL}/`;
+            
+            let fullPath = path;
+            if (env.NEXTCLOUD_BASE_DIR) {
+                const baseDir = env.NEXTCLOUD_BASE_DIR.replace(/^\/+|\/+$/g, "");
+                fullPath = baseDir ? `${baseDir}/${path}` : path;
+            }
+
+            const previewUrl = new URL(`${baseUrl}index.php/core/preview`);
+            // Ensure leading slash for the file parameter
+            const fileParam = fullPath.startsWith('/') ? fullPath : `/${fullPath}`;
+            previewUrl.searchParams.set("file", fileParam);
+            if (width) previewUrl.searchParams.set("x", width);
+            if (height) previewUrl.searchParams.set("y", height);
+            previewUrl.searchParams.set("forceIcon", "0");
+
+            const auth = Buffer.from(`${env.NEXTCLOUD_USER}:${env.NEXTCLOUD_PASSWORD}`).toString("base64");
+            
+            console.log(`Fetching preview: ${previewUrl.toString()} for file: ${fullPath}`);
+
+            try {
+                const response = await fetch(previewUrl.toString(), {
+                    headers: {
+                        "Authorization": `Basic ${auth}`
+                    }
+                });
+
+                if (response.ok) {
+                    buffer = await response.arrayBuffer();
+                    contentType = response.headers.get("Content-Type") || "image/png";
+                    
+                    return new Response(buffer, {
+                        headers: {
+                            "Content-Type": contentType,
+                            "Cache-Control": "public, max-age=86400",
+                            "Vary": "Accept-Encoding"
+                        }
+                    });
+                } else {
+                    console.warn(`Nextcloud preview failed (${response.status} ${response.statusText}) for ${fullPath}. Falling back to original.`);
+                }
+            } catch (fetchError) {
+                console.error(`Fetch error during preview request for ${fullPath}:`, fetchError);
+            }
+        }
+
+        // Fetch original via WebDAV (Fallback or no resize requested)
+        console.log(`Fetching original file via WebDAV: /${path}`);
+        const data = await client.getFileContents("/" + path);
+        buffer = data as ArrayBuffer;
+        contentType = mime.lookup(path) || "application/octet-stream";
         
-        return new Response(buffer as any, {
+        return new Response(buffer, {
             headers: {
                 "Content-Type": contentType,
-                "Cache-Control": "public, max-age=3600" // Cache for 1 hour
+                "Cache-Control": "public, max-age=86400",
+                "Vary": "Accept-Encoding"
             }
         });
     } catch (e) {