What it is

A compact notice that shows only on phones. On a desktop this page shows nothing - that is the demonstration. Open it on your phone, or use your browser's device mode.

When to use it

• A message that only matters on one device: an app download, a thumb-friendly checkout tip, a tap-to-call.
• Different offers for different devices (build two pop-ups, target each).

Why it works

Half your visitors are on a phone with a third of the screen; a pop-up sized and worded for that screen converts, a shrunken desktop one annoys.