diff --git a/plugins/ImageEncoder/ImageEncoder.php b/plugins/ImageEncoder/ImageEncoder.php
index 505f3df604..1eb3a6bbda 100644
--- a/plugins/ImageEncoder/ImageEncoder.php
+++ b/plugins/ImageEncoder/ImageEncoder.php
@@ -80,26 +80,30 @@ class ImageEncoder extends Plugin
     public function onResizeImage(Attachment $attachment, AttachmentThumbnail $thumbnail, int $width, int $height, bool $crop): bool
     {
         $old_limit = ini_set('memory_limit', Common::config('attachments', 'memory_limit'));
-
         try {
-            // -1 means load all pages, 'sequential' access means decode pixels on demand
-            // $image = Vips\Image::newFromFile(self::getPath($attachment), ['n' => -1, 'access' => 'sequential']);
-            $image = Vips\Image::thumbnail($attachment->getPath(), $width, ['height' => $height]);
-        } catch (Exception $e) {
-            Log::error(__METHOD__ . ' encountered exception: ' . print_r($e, true));
-            // TRANS: Exception thrown when trying to resize an unknown file type.
-            throw new Exception(_m('Unknown file type'));
+            try {
+                // -1 means load all pages, 'sequential' access means decode pixels on demand
+                // $image = Vips\Image::newFromFile(self::getPath($attachment), ['n' => -1, 'access' => 'sequential']);
+                $image = Vips\Image::thumbnail($attachment->getPath(), $width, ['height' => $height]);
+            } catch (Exception $e) {
+                Log::error(__METHOD__ . ' encountered exception: ' . print_r($e, true));
+                // TRANS: Exception thrown when trying to resize an unknown file type.
+                throw new Exception(_m('Unknown file type'));
+            }
+
+            if ($attachment->getPath() === $thumbnail->getPath()) {
+                @unlink($thumbnail->getPath());
+            }
+
+            if ($crop) {
+                $image = $image->smartcrop($width, $height);
+            }
+            $image->writeToFile($thumbnail->getPath());
+            unset($image);
+        } finally {
+            ini_set('memory_limit', $old_limit); // Restore the old memory limit
         }
 
-        if ($attachment->getPath() === $thumbnail->getPath()) {
-            @unlink($thumbnail->getPath());
-        }
-
-        $image->writeToFile($thumbnail->getPath());
-        unset($image);
-
-        ini_set('memory_limit', $old_limit); // Restore the old memory limit
-
         return Event::next;
     }
 }
diff --git a/src/Controller/Attachment.php b/src/Controller/Attachment.php
index 3980e3c8c2..f8a838f293 100644
--- a/src/Controller/Attachment.php
+++ b/src/Controller/Attachment.php
@@ -22,28 +22,55 @@
 namespace App\Controller;
 
 use App\Core\Controller;
-use App\Core\GSFile as M;
+use App\Core\DB\DB;
+use App\Core\GSFile;
+use App\Entity\AttachmentThumbnail;
+use App\Util\Common;
+use Symfony\Component\HttpFoundation\HeaderUtils;
 use Symfony\Component\HttpFoundation\Request;
 
 class Attachment extends Controller
 {
     public function attachment_show(Request $request, int $id)
     {
+        $res = GSFile::getAttachmentFileInfo($id);
+        return GSFile::sendFile($res['file_path'], $res['mimetype'], $res['title'], HeaderUtils::DISPOSITION_INLINE);
     }
 
     public function attachment_view(Request $request, int $id)
     {
-        $res = M::getAttachmentFileInfo($id);
-        return M::sendFile($res['file_path'], $res['mimetype'], $res['title'], 'inline');
+        $res = GSFile::getAttachmentFileInfo($id);
+        return GSFile::sendFile($res['file_path'], $res['mimetype'], $res['title'], HeaderUtils::DISPOSITION_INLINE);
     }
 
     public function attachment_download(Request $request, int $id)
     {
-        $res = M::getAttachmentFileInfo($id);
-        return M::sendFile($res['file_path'], $res['mimetype'], $res['title'], 'attachment');
+        $res = GSFile::getAttachmentFileInfo($id);
+        return GSFile::sendFile($res['file_path'], $res['mimetype'], $res['title'], HeaderUtils::DISPOSITION_ATTACHMENT);
     }
 
     public function attachment_thumbnail(Request $request, int $id)
     {
+        $attachment = DB::findOneBy('attachment', ['id' => $id]);
+        if (!is_null($attachment->getScope())) {
+            // && ($attachment->scope | VisibilityScope::PUBLIC) != 0
+            // $user = Common::ensureLoggedIn();
+            assert(false, 'Attachment scope not implemented');
+        }
+
+        // TODO rate limit, limit to known sizes
+
+        $max_width  = Common::config('thumbnail', 'width');
+        $max_height = Common::config('thumbnail', 'height');
+        $width      = Common::clamp($this->int('w') ?: $max_width,  min: 0, max: $max_width);
+        $height     = Common::clamp($this->int('h') ?: $max_height, min: 0, max: $max_height);
+        $crop       = $this->bool('c') ?: false;
+
+        $thumbnail = AttachmentThumbnail::getOrCreate(attachment: $attachment, width: $width, height: $height, crop: $crop);
+
+        $filename = $thumbnail->getFilename();
+        $path     = $thumbnail->getPath();
+
+        return GSFile::sendFile(filepath: $path, mimetype: $attachment->getMimetype(), output_filename: $filename, disposition: 'inline');
     }
 }
diff --git a/src/Core/GSFile.php b/src/Core/GSFile.php
index 601bd764dd..5e8b9c3f87 100644
--- a/src/Core/GSFile.php
+++ b/src/Core/GSFile.php
@@ -86,7 +86,7 @@ class GSFile
             [
                 'Content-Description' => 'File Transfer',
                 'Content-Type'        => $mimetype,
-                'Content-Disposition' => HeaderUtils::makeDisposition($disposition, $output_filename ?: _m('Untitled attachment')),
+                'Content-Disposition' => HeaderUtils::makeDisposition($disposition, $output_filename ?: _m('Untitled attachment'), _m('Untitled attachment')),
                 'Cache-Control'       => 'public',
             ],
             $public = true,
diff --git a/src/Routes/Attachments.php b/src/Routes/Attachments.php
new file mode 100644
index 0000000000..83b9ab6311
--- /dev/null
+++ b/src/Routes/Attachments.php
@@ -0,0 +1,49 @@
+<?php
+
+// {{{ License
+
+// This file is part of GNU social - https://www.gnu.org/software/social
+//
+// GNU social is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// GNU social is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with GNU social.  If not, see <http://www.gnu.org/licenses/>.
+
+// }}}
+
+/**
+ * Define social's attachment routes
+ *
+ * @package  GNUsocial
+ * @category Router
+ *
+ * @author    Diogo Cordeiro <mail@diogo.site>
+ * @author    Hugo Sales <hugo@hsal.es>
+ * @copyright 2020-2021 Free Software Foundation, Inc http://www.fsf.org
+ * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
+ */
+
+namespace App\Routes;
+
+use App\Controller as C;
+use App\Core\Router\RouteLoader;
+
+abstract class Attachments
+{
+    public static function load(RouteLoader $r): void
+    {
+        $r->connect('attachment_show',      '/attachment/{id<\d+>}',           [C\Attachment::class, 'attachment_show']);
+        $r->connect('attachment_view',      '/attachment/{id<\d+>}/view',      [C\Attachment::class, 'attachment_view']);
+        $r->connect('attachment_download',  '/attachment/{id<\d+>}/download',  [C\Attachment::class, 'attachment_download']);
+        $r->connect('attachment_thumbnail', '/attachment/{id<\d+>}/thumbnail', [C\Attachment::class, 'attachment_thumbnail']);
+        $r->connect('thumbnail',            '/thumbnail/{id<\d+>}',            [C\Attachment::class, 'attachment_thumbnail']);
+    }
+}
diff --git a/src/Routes/Main.php b/src/Routes/Main.php
index 7a68cc3bbc..04c370502a 100644
--- a/src/Routes/Main.php
+++ b/src/Routes/Main.php
@@ -69,11 +69,5 @@ abstract class Main
         foreach (['personal_info', 'avatar', 'notifications', 'account'] as $s) {
             $r->connect('settings_' . $s, '/settings/' . $s, [C\UserPanel::class, $s]);
         }
-
-        // Attachments
-        $r->connect('attachment_show', '/attachment/{id<\d+>}', [C\Attachment::class, 'attachment_show']);
-        $r->connect('attachment_view', '/attachment/{id<\d+>}/view', [C\Attachment::class, 'attachment_view']);
-        $r->connect('attachment_download', '/attachment/{id<\d+>}/download', [C\Attachment::class, 'attachment_download']);
-        $r->connect('attachment_thumbnail', '/attachment/{id<\d+>}/thumbnail', [C\Attachment::class, 'attachment_thumbnail']);
     }
 }