diff --git a/README.md b/README.md
index 9184729..374674f 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ This is a cli tool to compress image quickly and effectively by using [tinypng](
 - support to replace or dump compressed images
 - support to avoid repeat compress
 - support to display compress result
+- support '.png', '.jpg', 'jpeg', '.webp'
 
 ## QUICK START