Iframe
An iframe (inline frame) is an HTML element that embeds one web page inside another, rendering it in its own contained box with its own styles and scripts. It's the standard way to drop a widget built and hosted by one provider onto a website owned by someone else, without the two codebases interfering with each other.
Because an iframe's content is sandboxed from the surrounding page, a widget rendered in one can't be broken by the host site's CSS, and the host site's styles can't leak into the widget either - each renders independently.
The tradeoff is sizing: a plain iframe has a fixed height unless something actively resizes it. Widgets that need to grow or shrink with their content typically use a postMessage event to tell the surrounding page how tall to make the iframe, so it never clips or leaves a gap.
Why it matters for hosts
Both RentalBeam widgets are React pages served inside an iframe, whether embedded via the JavaScript snippet or a bare iframe tag directly. The auto-resize behavior is built in, so the widget always shows its full content without a fixed-height guess.
Related terms
Other glossary terms that come up alongside this one.
See this in the product.
See the developer reference