diff --git a/src/perf.js b/src/perf.js
new file mode 100644
index 0000000..5bea916
--- /dev/null
+++ b/src/perf.js
@@ -0,0 +1 @@
+document.querySelectorAll("img[data-src]").forEach(img => { img.src = img.dataset.src; });