.OBB File

File extension obb is nowadays mostly related to Google Android mobile operating system for smart phones and tablets

OBB is short for Opaque Binary Blob files (obb file), special archives created with the JOBB tool from Android SDK (now Android Studio).

This feature was introduced in Android 2.3 Gingerbread and allows developer to create apps larger than 50 MB. This is because Google Play (previously Android Market) does not allow apk files bigger than this value.

In essence, an obb file is an encrypted archive that contains data above the 50 MB limit, which in turn means that more multimedia content, HD graphics for apps. It can also be shared across multiple apps, for example navigation maps.

For games it means that it is possible for developers to offer more complex, graphics rich apps through the store.

Files with obb extension can be usually found as special, encrypted archives for Android APKs that contain additional content, graphics, map packs, multimedia files and more. Common for all large and complex Android apps.

How to open:

These *.obb files are used together with a corresponding .apk installation packages to add aditional content.

How to convert:

It seems that you cannot just simply convert obb files to anything. However, some SKD tools can be used to explore the files.