.VDEX File Extension

In 2019, Google introduced the VDEX file format. The VDEX format was another iteration in Google's attempts to optimize Android apps' compilation and loading process. When a user installs an Android app, Android automatically optimizes that app and creates a corresponding .OAT and VDEX file. Referencing these files, rather than recompiling apps upon each load or update, allows Android to load apps more quickly, creating a better user experience.

VDEX files contain optimized versions of previously validated DEX (Dalvik Executable) files, which Android has noted that it does not need to re-extract and re-verify when recompiling an app. VDEX files are typically stored alongside OAT files, in an Android device's /​data/​dalvik-cache directory.

VDEX files are not meant to be opened. If necessary, Android developers can use vdexExtractor (cross-platform) to extract DEX files from a VDEX file.