diff --git a/.changeset/evil-lamps-refuse.md b/.changeset/evil-lamps-refuse.md
new file mode 100644
index 0000000000000..a345e27815071
--- /dev/null
+++ b/.changeset/evil-lamps-refuse.md
@@ -0,0 +1,5 @@
+---
+"gradio": patch
+---
+
+feat:WIP: Optimize /file route
diff --git a/gradio/routes.py b/gradio/routes.py
index 077c513327439..2ea7fd49a1f6f 100644
--- a/gradio/routes.py
+++ b/gradio/routes.py
@@ -439,7 +439,11 @@ async def file(path_or_url: str, request: fastapi.Request):
             if in_blocklist or is_dir:
                 raise HTTPException(403, f"File not allowed: {path_or_url}.")
 
-            created_by_app = str(abs_path) in set().union(*blocks.temp_file_sets)
+            created_by_app = False
+            for temp_file_set in blocks.temp_file_sets:
+                if abs_path in temp_file_set:
+                    created_by_app = True
+                    break
             in_allowlist = any(
                 utils.is_in_or_equal(abs_path, allowed_path)
                 for allowed_path in blocks.allowed_paths