Google has announced a new method of updating your apps on the Play Store. A previous change had reduced the size of updates by 47% on average, but this new one can reduce the size by a further 65%.
The new method is called File-by-File patching. Since APKs are zipped up and compressed, one can’t just replace a single file without changing the entire file’s compressed output. Therefore this new method will decompress both the old and the new APK, apply the patch from the new APK, and compress the APK on your device. While this takes less data, it takes more time and processing power.
Because of these drawbacks, Google is limiting this new update method to automatic updates that it can do in the background. Manually updating apps won’t utilize this new technique in saving data.
Thankfully, developers won’t have to change anything to utilize this new update system. It’s all on Google’s end. If you want to learn more about File-by-File patching, hit the source link!
Source: Android Developers Blog