Slide-In Popup
A small panel that slides in from a bottom or side corner of the screen without covering the main content or blocking interaction with the page.
A slide-in popup animates into a corner, usually bottom right, and stays there until dismissed. The page remains scrollable and clickable behind it, so it reads as a suggestion rather than a demand. It is the least disruptive way to put a form on screen while the visitor is still reading.
Slide-ins fit long-form content and blog posts, where a scroll-depth trigger can bring one in after the visitor has read enough to care. They also work as a persistent secondary offer, such as a related guide or a chat prompt, that sits beside the content instead of in front of it.
The trade-off is attention. A slide-in gets fewer eyes than a centered modal because it does not force a decision, so its conversion rate per view is usually lower even though it costs less goodwill. On mobile, keep it compact and make the close control easy to hit, since a panel that covers the bottom of a small screen behaves like a full modal in practice.
See it in practice