audioOS 9.9.18.4.1 (build 22L261) is an official Apple over-the-air update for the HomePod, released on 2025-04-16T17:28:36Z. The update package is 72.8 MB. This is a delta (partial) update that requires 18.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: fd602dc4c198b6bc1c463c61f966b8ddb0ce2b80.zip.