audioOS 9.9.18.4.1 (build 22L261) is an official Apple over-the-air update for the HomePod (2nd generation), released on 2025-04-16T17:28:47Z. The update package is 1.25 GB. This is a delta (partial) update that requires 17.3 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: fbcd4746de1abfc8140a375d68a1758d217a97e77212b7a33b3efd2905aecd73.aea.