diff --git a/core/video/youtube.py b/core/video/youtube.py
index 9f51181e..ff392cf3 100644
--- a/core/video/youtube.py
+++ b/core/video/youtube.py
@@ -168,9 +168,10 @@ def _cookie_opts():
     try:
         from config.settings import config_manager
         cb = config_manager.get("youtube.cookies_browser", "")
-        if cb:
+        # 'custom' = the paste-cookies.txt sentinel (not a yt-dlp browser); skip it here.
+        if cb and cb != "custom":
             return {"cookiesfrombrowser": (cb,)}
-    except Exception:
+    except Exception:  # noqa: S110 - cookie config is best-effort; extraction still works without it
         pass
     return {}
 
diff --git a/core/youtube_client.py b/core/youtube_client.py
index a1cef67b..7ac6daa0 100644
--- a/core/youtube_client.py
+++ b/core/youtube_client.py
@@ -222,7 +222,7 @@ class YouTubeClient(DownloadSourcePlugin):
 
         # Cookie support — use browser cookies for YouTube auth
         from config.settings import config_manager
-        cookies_browser = config_manager.get('youtube.cookies_browser', '')
+        cookies_browser = ('' if (_cb := config_manager.get('youtube.cookies_browser', '')) == 'custom' else _cb)
         if cookies_browser:
             self.download_opts['cookiesfrombrowser'] = (cookies_browser,)
 
@@ -309,7 +309,7 @@ class YouTubeClient(DownloadSourcePlugin):
         """Reload YouTube settings from config (called when settings are saved)."""
         from config.settings import config_manager
         self._download_delay = config_manager.get('youtube.download_delay', 3)
-        cookies_browser = config_manager.get('youtube.cookies_browser', '')
+        cookies_browser = ('' if (_cb := config_manager.get('youtube.cookies_browser', '')) == 'custom' else _cb)
         if cookies_browser:
             self.download_opts['cookiesfrombrowser'] = (cookies_browser,)
         elif 'cookiesfrombrowser' in self.download_opts:
@@ -736,7 +736,7 @@ class YouTubeClient(DownloadSourcePlugin):
                     'default_search': 'ytsearch',
                     'user_agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36',
                 }
-                cookies_browser = config_manager.get('youtube.cookies_browser', '')
+                cookies_browser = ('' if (_cb := config_manager.get('youtube.cookies_browser', '')) == 'custom' else _cb)
                 if cookies_browser:
                     ydl_opts['cookiesfrombrowser'] = (cookies_browser,)
 
@@ -816,7 +816,7 @@ class YouTubeClient(DownloadSourcePlugin):
                 }
 
                 # Add cookie support for search (avoids bot detection)
-                cookies_browser = config_manager.get('youtube.cookies_browser', '')
+                cookies_browser = ('' if (_cb := config_manager.get('youtube.cookies_browser', '')) == 'custom' else _cb)
                 if cookies_browser:
                     ydl_opts['cookiesfrombrowser'] = (cookies_browser,)
 
@@ -1180,7 +1180,7 @@ class YouTubeClient(DownloadSourcePlugin):
                 'user_agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36',
             }
 
-            cookies_browser = config_manager.get('youtube.cookies_browser', '')
+            cookies_browser = ('' if (_cb := config_manager.get('youtube.cookies_browser', '')) == 'custom' else _cb)
             if cookies_browser:
                 download_opts['cookiesfrombrowser'] = (cookies_browser,)
 
diff --git a/web_server.py b/web_server.py
index 0b14d5a3..3979a13f 100644
--- a/web_server.py
+++ b/web_server.py
@@ -14747,7 +14747,8 @@ def _youtube_cookie_opts():
     opts = {}
     try:
         cb = config_manager.get('youtube.cookies_browser', '')
-        if cb:
+        # 'custom' = the paste-cookies.txt sentinel (not a yt-dlp browser); skip it here.
+        if cb and cb != 'custom':
             opts['cookiesfrombrowser'] = (cb,)
     except Exception:  # noqa: S110 - cookie config is best-effort; resolve still works without it
         pass