Google seeds new delta algorithm to reduce app updates size
Google has started seeding their new delta algorithm to apps in the Play Store to reduce the size of app updates.
The delta algorithm is called “bsdiff” and as the mentioned earlier, it reduces the data that needs to be transferred for app installs and updates. It does this by only downloading the changes (deltas) to APK files then merges them with the existing files. So far, the algorithm has been seeded to approximately 98% of apps updates form the Play Store.
According to Google, bsdiff “further reduces patches by up to 50% or more compared to the previous algorithm.” Here’s their sample comparison with the Chrome app:
Google has also applied the new algorithm to APK Expansion Files – files that the app downloads after installing the initial APK – to reduce the download size of initial installs by 12%, and updates by 65% on average.
That said, the new algorithm not only will benefit developers and their apps, but will also save users precious bandwidth, especially those on mobile, when downloading updates.