audioOS 9.9.15.4 (build 19L440) is an official Apple over-the-air update for the HomePod mini, released on 2022-03-14T17:12:42Z. The update package is 401.68 MB. This is a delta (partial) update that requires 15.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 23d771ff1a1b63a8e3c98fdc10d9265ba8464d03.zip.