diff --git a/Base/res/html/misc/opacity.html b/Base/res/html/misc/opacity.html
new file mode 100644
index 0000000000..4dfa51770c
--- /dev/null
+++ b/Base/res/html/misc/opacity.html
@@ -0,0 +1,70 @@
+<html>
+    <head>
+        <style>
+            .op-100 {
+            background: green;
+            opacity: 1.0;
+            }
+            .op-70 {
+            background: green;
+            opacity: 70%;
+            }
+            .op-50 {
+            background: green;
+            opacity: 0.5;
+            }
+            .op-30 {
+            background: green;
+            opacity: 30%;
+            }
+            .op-0 {
+            background: green;
+            opacity: 0;
+            }
+            .red {
+            background: red;
+            }
+        </style>
+    </head>
+    <body>
+        <div class=op-100>
+            100% opacity
+        </div>
+        <div class=op-70>
+            70% opacity
+        </div>
+        <div class=op-50>
+            50% opacity
+        </div>
+        <div class=op-30>
+            30% opacity
+        </div>
+        <div class=op-0>
+            0% opacity
+        </div>
+        <div class="red">
+            Blending with other colors
+            <div class=op-100>
+                100% opacity
+            </div>
+            <div class=op-70>
+                70% opacity
+            </div>
+            <div class=op-50>
+                50% opacity
+            </div>
+            <div class=op-30>
+                30% opacity
+            </div>
+            <div class=op-0>
+                0% opacity
+            </div>
+        </div>
+        <div class=op-70>
+            70% opacity
+            <div class=op-50>
+                50% opacity inside 70% opacity
+            </div>
+        </div>
+    </body>
+</html>
diff --git a/Base/res/html/misc/welcome.html b/Base/res/html/misc/welcome.html
index 8f34b1298e..dbc740f4bd 100644
--- a/Base/res/html/misc/welcome.html
+++ b/Base/res/html/misc/welcome.html
@@ -47,6 +47,7 @@
     <p>Some small test pages:</p>
     <ul>
         <li><a href="calc.html">calc Property</a></li>
+        <li><a href="opacity.html">CSS opacity property</a></li>
         <li><a href="justify-content.html">Flexbox justify-content</a></li>
         <li><a href="lists.html">Lists</a></li>
         <li><a href="text-decoration.html">Text-decoration</a></li>
