diff --git a/doc/classes/JavaScript.xml b/doc/classes/JavaScript.xml
index e202bb6aef1..0ff460daeb5 100644
--- a/doc/classes/JavaScript.xml
+++ b/doc/classes/JavaScript.xml
@@ -47,6 +47,13 @@
 				If [code]use_global_execution_context[/code] is [code]true[/code], the code will be evaluated in the global execution context. Otherwise, it is evaluated in the execution context of a function within the engine's runtime environment.
 			</description>
 		</method>
+		<method name="force_fs_sync">
+			<return type="void" />
+			<description>
+				Force synchronization of the persistent file system (when enabled).
+				[b]Note:[/b] This is only useful for modules or extensions that can't use [File] to write files.
+			</description>
+		</method>
 		<method name="get_interface">
 			<return type="JavaScriptObject" />
 			<argument index="0" name="interface" type="String" />
diff --git a/platform/javascript/api/api.cpp b/platform/javascript/api/api.cpp
index aa05f5898a2..28d0c073bca 100644
--- a/platform/javascript/api/api.cpp
+++ b/platform/javascript/api/api.cpp
@@ -73,6 +73,7 @@ void JavaScript::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("download_buffer", "buffer", "name", "mime"), &JavaScript::download_buffer, DEFVAL("application/octet-stream"));
 	ClassDB::bind_method(D_METHOD("pwa_needs_update"), &JavaScript::pwa_needs_update);
 	ClassDB::bind_method(D_METHOD("pwa_update"), &JavaScript::pwa_update);
+	ClassDB::bind_method(D_METHOD("force_fs_sync"), &JavaScript::force_fs_sync);
 	ADD_SIGNAL(MethodInfo("pwa_update_available"));
 }
 
@@ -111,6 +112,8 @@ bool JavaScript::pwa_needs_update() const {
 Error JavaScript::pwa_update() {
 	return ERR_UNAVAILABLE;
 }
+void JavaScript::force_fs_sync() {
+}
 void JavaScript::download_buffer(Vector<uint8_t> p_arr, const String &p_name, const String &p_mime) {
 }
 #endif
diff --git a/platform/javascript/api/javascript_singleton.h b/platform/javascript/api/javascript_singleton.h
index d346a1ce90f..1836763c5f5 100644
--- a/platform/javascript/api/javascript_singleton.h
+++ b/platform/javascript/api/javascript_singleton.h
@@ -61,6 +61,7 @@ public:
 	void download_buffer(Vector<uint8_t> p_arr, const String &p_name, const String &p_mime = "application/octet-stream");
 	bool pwa_needs_update() const;
 	Error pwa_update();
+	void force_fs_sync();
 
 	static JavaScript *get_singleton();
 	JavaScript();
diff --git a/platform/javascript/javascript_singleton.cpp b/platform/javascript/javascript_singleton.cpp
index 6ef80b9f22b..595e00ed04c 100644
--- a/platform/javascript/javascript_singleton.cpp
+++ b/platform/javascript/javascript_singleton.cpp
@@ -351,6 +351,11 @@ void JavaScript::download_buffer(Vector<uint8_t> p_arr, const String &p_name, co
 bool JavaScript::pwa_needs_update() const {
 	return OS_JavaScript::get_singleton()->pwa_needs_update();
 }
+
+void JavaScript::force_fs_sync() {
+	OS_JavaScript::get_singleton()->force_fs_sync();
+}
+
 Error JavaScript::pwa_update() {
 	return OS_JavaScript::get_singleton()->pwa_update();
 }
diff --git a/platform/javascript/os_javascript.cpp b/platform/javascript/os_javascript.cpp
index 6f26cc1bb7f..698efcea463 100644
--- a/platform/javascript/os_javascript.cpp
+++ b/platform/javascript/os_javascript.cpp
@@ -1145,6 +1145,12 @@ Error OS_JavaScript::pwa_update() {
 	return godot_js_pwa_update() ? FAILED : OK;
 }
 
+void OS_JavaScript::force_fs_sync() {
+	if (is_userfs_persistent()) {
+		idb_needs_sync = true;
+	}
+}
+
 bool OS_JavaScript::is_userfs_persistent() const {
 	return idb_available;
 }
diff --git a/platform/javascript/os_javascript.h b/platform/javascript/os_javascript.h
index 56355c2dbf2..3fd516ee8b3 100644
--- a/platform/javascript/os_javascript.h
+++ b/platform/javascript/os_javascript.h
@@ -125,6 +125,7 @@ public:
 	bool check_size_force_redraw();
 	bool pwa_needs_update() const { return pwa_is_waiting; }
 	Error pwa_update();
+	void force_fs_sync();
 
 	// Override return type to make writing static callbacks less tedious.
 	static OS_JavaScript *get_singleton();