When you’re dealing with 2 billion active users, there’s a lot of data being sent out with software updates and making those updates smaller benefits everyone. To this end, Google is bringing Brotli compression to OTA updates, making for smaller, faster updates.
The change to compression on OTA updates was found by XDA-Developers, who have broken down the reasons for the change. It essentially comes down to the fact that Brotli can save significant amounts of data and it’s fast to decompress.
Developed by Googlers, based on gzip and deflate specifications, Brotli was initially used for compressing web fonts. It’s static data like this that is where Brotli shines. It’s great for compressing static data like web fonts, an update file or webpage, but it’s not great for dynamic data due to the Brotli algorithm being slow to compress.
The speed at which Brotli can decompress data though makes it ideal for OTA updates. It’s a smaller package delivered to your device, and once on your device it can unzip quickly – and then get patched into your OS in a faster time. XDA rightly points out that owners of devices like the Pixel phones who use the A/B partition scheme which lets updates seamlessly install in the background, won’t particularly notice the update speed.
The size of the update also won’t particularly matter to anyone who downloads the updates on Wifi, but still, it’s a good move forward for Google when they’re targeting developing markets where saving a couple of MB makes a massive difference to users.