diff --git a/check-diff.sh b/check-diff.sh
new file mode 100644
index 0000000..4d46c39
--- /dev/null
+++ b/check-diff.sh
@@ -0,0 +1,35 @@
+#! /bin/sh
+#
+
+set -x
+if [ "$#" -eq 0 ] || [ "$#" -gt 1 ]; then
+  echo takes only one argument
+  exit 1
+fi
+
+if [ ! -e "${1}" ]; then
+  echo cannot find "${1}"
+  exit 1
+fi
+
+# shellcheck source=./env_files/checkdiff-example.env
+. "${1}"
+
+remote_copy_path=$(mktemp -d)
+rsync \
+  --archive \
+  --checksum \
+  --human-readable \
+  "${REMOTE_SSH_STRING}":"${REMOTE_ROOT_PATH}${FOLDER_PATH}/" \
+  "${remote_copy_path}"
+
+local_copy_path=$(mktemp -d)
+rsync \
+  --archive \
+  --checksum \
+  --exclude-from="${EXCLUDEFILE_PATH}" \
+  --human-readable \
+  "${LOCAL_ROOT_PATH}${FOLDER_PATH}/" \
+  "${local_copy_path}"
+
+kdiff3 "${local_copy_path}" "${remote_copy_path}"
diff --git a/env_files/checkdiff-example.env b/env_files/checkdiff-example.env
new file mode 100644
index 0000000..e690b45
--- /dev/null
+++ b/env_files/checkdiff-example.env
@@ -0,0 +1,5 @@
+REMOTE_SSH_STRING=<sshconfig hostname>
+REMOTE_ROOT_PATH=</var/www/example.com/www>
+LOCAL_ROOT_PATH=</home/user/dev/www>
+FOLDER_PATH=</wp-content/themes/bar>
+EXCLUDEFILE_PATH=<./deployment/example.com.bar.exclude>