audioOS 9.9.17.4 (build 21L227) is an official Apple over-the-air update for the HomePod, released on 2024-03-07T18:16:22Z. The update package is 1.21 GB. This is a delta (partial) update that requires 16.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e82b8f338cdb7c58234c6fa1f65d402173f343e0.zip.