diff --git a/backend/MediaCacheManager.py b/backend/MediaCacheManager.py
index 474c191..5faa77e 100644
--- a/backend/MediaCacheManager.py
+++ b/backend/MediaCacheManager.py
@@ -148,7 +148,7 @@ class MediaChunkHolder(object):
 
 
 class MediaChunkHolderManager(object):
-    MAX_CACHE_SIZE = 2**32  # 4GB
+    MAX_CACHE_SIZE = 2**31  # 2GB
     current_cache_size: int = 0
     # chunk unique id -> ChunkHolder
     disk_chunk_cache: diskcache.Cache
diff --git a/backend/api.py b/backend/api.py
index 5849010..9c66ccf 100644
--- a/backend/api.py
+++ b/backend/api.py
@@ -85,7 +85,7 @@ async def search_tg_file_list(body: TgToFileListRequestBody):
             chat_id = apiutils.get_message_chat_id_from_dict(msg_info)
             msg_id = apiutils.get_message_msg_id_from_dict(msg_info)
             msg_info["file_name"] = file_name
-            msg_info["download_url"] = f"{param.base.exposed_url}/tg/api/v1/file/get/{chat_id}/{msg_id}/{file_name}"
+            msg_info["download_url"] = f"{param.base.exposed_url}/tg/api/v1/file/get/{chat_id}/{msg_id}/{quote(file_name)}"
             msg_info["src_tg_link"] = f"https://t.me/c/{chat_id}/{msg_id}"
             res_dict.append(msg_info)
 
@@ -127,7 +127,7 @@ async def get_tg_file_list(body: TgToFileListRequestBody):
             msg_info = json.loads(item.to_json())
             msg_info["file_name"] = file_name
             msg_info["download_url"] = (
-                f"{param.base.exposed_url}/tg/api/v1/file/get/{body.chat_id}/{item.id}/{file_name}?sign={body.token}"
+                f"{param.base.exposed_url}/tg/api/v1/file/get/{body.chat_id}/{item.id}/{quote(file_name)}?sign={body.token}"
             )
             res_dict.append(msg_info)
 
diff --git a/backend/api_implement.py b/backend/api_implement.py
index 063dac9..721aae8 100644
--- a/backend/api_implement.py
+++ b/backend/api_implement.py
@@ -39,7 +39,9 @@ async def link_convert(link: str) -> str:
     file_name = apiutils.get_message_media_name(msg)
     param = configParse.get_TgToFileSystemParameter()
     sign = clients_mgr.generate_sign(client.session_name, EnumSignLevel.VIST)
-    url = f"{param.base.exposed_url}/tg/api/v1/file/get/{utils.get_peer_id(msg.peer_id)}/{msg.id}/{file_name}?sign={sign}"
+    url = (
+        f"{param.base.exposed_url}/tg/api/v1/file/get/{utils.get_peer_id(msg.peer_id)}/{msg.id}/{quote(file_name)}?sign={sign}"
+    )
     return url