diff --git a/scripts/format.sh b/scripts/format.sh
new file mode 100755
index 0000000..c116dfc
--- /dev/null
+++ b/scripts/format.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+set -eu
+cd "$(dirname "$0")"
+cd ..
+echo "Entering directory '$PWD'"
+set -x
+tidy \
+    --indent yes \
+    --quiet yes \
+    --show-filename yes \
+    --tidy-mark no \
+    --write-back yes \
+    www/*.html