diff --git a/.gitignore b/.gitignore
index 23f9b91..304c539 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 nohup.out
 venv
 downloads
+cookies.txt
diff --git a/app.py b/app.py
index 530f23f..c41151e 100644
--- a/app.py
+++ b/app.py
@@ -53,31 +53,39 @@ _USER_AGENTS = [
 def _random_ua():
     return random.choice(_USER_AGENTS)
 
+# ---------------------------------------------------------------------------
+# Cookies file — place a cookies.txt (Netscape format, exported from your
+# browser while logged into YouTube) next to app.py to authenticate requests.
+# Authenticated sessions are routed to faster CDN endpoints and bypass the
+# throttling YouTube applies to anonymous traffic.
+# The file is optional; if absent yt-dlp falls back to anonymous mode.
+# ---------------------------------------------------------------------------
+COOKIES_FILE = os.path.join(os.path.dirname(__file__), "cookies.txt")
+
 # ---------------------------------------------------------------------------
 # Base yt-dlp options shared by all calls.
 #
-# • cachedir          – persists solved JS sig/nsig to disk; node only re-runs
-#                       when YouTube rotates their player (every few days).
-# • sleep_interval /
-#   max_sleep_interval– small random sleep between fragment requests;
-#                       makes traffic pattern look more human.
-# • http_chunk_size   – stream in 10 MB chunks rather than one giant request;
-#                       reduces the chance of a mid-transfer 429.
-# • js_runtimes       – use local node v20+ for JS challenge solving.
+# cookiefile      - browser cookies for authenticated (fast) CDN routing.
+# cachedir        - persists solved JS sig/nsig to disk so node only re-runs
+#                   when YouTube rotates their player (every few days).
+# http_chunk_size - 10 MB chunks; plays nicer with YouTube CDN.
+# js_runtimes     - use local node v20+ for JS challenge solving.
+#
+# NOTE: sleep_interval intentionally removed — it was artificially capping
+#       download speed. Anti-throttle measures live in the frontend instead.
 # ---------------------------------------------------------------------------
 def _base_opts(extra=None):
     opts = {
-        "quiet": True,
         "cachedir": CACHE_DIR,
         "js_runtimes": {"node": {"executable": "/usr/bin/node"}},
         "http_headers": {"User-Agent": _random_ua()},
-        "sleep_interval": 1,
-        "max_sleep_interval": 3,
-        "http_chunk_size": 10 * 1024 * 1024,   # 10 MB
+        "http_chunk_size": 10 * 1024 * 1024,
         "socket_timeout": 30,
         "retries": 6,
         "fragment_retries": 6,
     }
+    if os.path.isfile(COOKIES_FILE):
+        opts["cookiefile"] = COOKIES_FILE
     if extra:
         opts.update(extra)
     return opts