The hx-swap-oob attribute allows you to specify that some content in a response should be swapped into the DOM somewhere other than the target, that is "Out of Band". This allows you to piggy back updates to other element updates on a response.

Consider the following response HTML:

<div id="alerts" hx-swap-oob="true">

The first div will be swapped into the target the usual manner. The second div, however, will be swapped in as a replacement for the element with the id alerts, and will not end up in the target.

The value of the hx-swap-oob can be:

If the value is true or outerHTML (which are equivalent) the element will be swapped inline.

If a swap value is given, that swap strategy will be used.

If a selector is given, the first element matching that selector will be swapped. If not, the element with an ID matching the new content will be swapped.