diff --git a/more/free-programming-playgrounds-zh.md b/more/free-programming-playgrounds-zh.md
index a2b10c15f..6b90e056b 100644
--- a/more/free-programming-playgrounds-zh.md
+++ b/more/free-programming-playgrounds-zh.md
@@ -1,8 +1,14 @@
 ### Index
 
 * [Dart](#dart)
+* [JavaScript](#javascript)
 
 
 ### Dart
 
 * [DartPad](https://dartpad.cn)
+
+
+### JavaScript
+
+* [码上掘金](https://code.juejin.cn) - 北京北比信息技术有限公司