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 478.76 MB. This is a delta (partial) update that requires 15.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 66989f918140b8871298e406445e12dbf085b7dc.zip.