audioOS 9.9.18.4

audioOS 9.9.18.4 (build 22L255) is an official Apple over-the-air update for the HomePod, released on 2025-03-31T17:29:32Z. The update package is 1.75 GB. This is a delta (partial) update that requires 15.5.1 to already be installed on the device - it cannot be applied from scratch. This update is no longer signed by Apple, meaning it can no longer be downloaded and applied on-device through Settings.

The OTA payload file is 51fee0d0271d58adef4355508f412e993ba05248.zip.