diff --git a/ui/index-fallback.js b/ui/index-fallback.js
new file mode 100644
index 0000000..70161ad
--- /dev/null
+++ b/ui/index-fallback.js
@@ -0,0 +1,8 @@
+document.body.innerHTML = `
+<div class="center-parent">
+	<div class="center">
+		<p>⚠ This browser is not supported: the application relies on <a href="https://caniuse.com/webusb">WebUSB</a> and <a href="https://caniuse.com/import-maps">Import Maps</a>.
+		<p>Don't know how you got here? Check out the <a href="https://web.dev/porting-libusb-to-webusb/">blog post</a> or the <a href="https://github.com/GoogleChromeLabs/web-gphoto2">repo</a>!
+	</div>
+</div>
+`;