audioOS 9.9.18.4.1 (build 22L261) is an official Apple over-the-air update for the HomePod (2nd generation), released on 2025-04-16T17:28:45Z. The update package is 1.47 GB. This is a delta (partial) update that requires 16.4 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: ff1f4a4e8fabe1cae340b06f7da1a4402c1530ceddf19bc40020ab253c6eab5e.aea.