diff --git a/testing/web-platform/tests/encoding/sniffing.html b/testing/web-platform/tests/encoding/sniffing.html
new file mode 100644
index 0000000000000..480be55515e8c
--- /dev/null
+++ b/testing/web-platform/tests/encoding/sniffing.html
@@ -0,0 +1,12 @@
+<!doctype html>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<title>No (UTF-8) sniffing allowed</title>
+<div id=log></div>
+<div id=content> Hello World! </div>
+<script>
+test(() => {
+  assert_equals(document.getElementById("content").textContent, "\u00C2\u20AC\u00C2\u20AC Hello World! \u00C2\u20AC\u00C2\u20AC");
+  assert_equals(document.characterSet, "windows-1252");
+});
+</script>
