diff --git a/content/notes/cosc-203.md b/content/notes/cosc-203.md
index 5f1015e1c..a0184a6c2 100644
--- a/content/notes/cosc-203.md
+++ b/content/notes/cosc-203.md
@@ -10,6 +10,7 @@ tags:
 
 - [page](https://cosc203.cspages.otago.ac.nz)
 - [labs](https://cosc203.cspages.otago.ac.nz/labs/)
+- [html validator](https://validator.w3.org/nu/)
 
 # Assignments
 - [front end project](notes/front-end-project)