diff --git a/guide/english/user-experience-design/prototyping/index.md b/guide/english/user-experience-design/prototyping/index.md
index 68d85951e16..0f3a8b02e64 100644
--- a/guide/english/user-experience-design/prototyping/index.md
+++ b/guide/english/user-experience-design/prototyping/index.md
@@ -34,3 +34,4 @@ Some popular prototyping tools among UX designers include:
 - Figma - https://figma.com
 - UXPin - https://www.uxpin.com/
 - Framer - https://framer.com
+- Proto.io - https://proto.io/