MCWORLD files are used in Minecraft. They are zipped packages of world files. Players can share worlds by saving them as MCWORLD files. Other players download and open MCWORLD files to play the shared world. File extensions show associated programs. Many Minecraft extensions start with ‘.mc’. MCWORLD files are zipped world packages. Open them without Minecraft as follows. Use a zip program to expand MCWORLD files. Save individual files from the zip. Preview files in your browser. Other Minecraft file extensions are: .mca – terrain blocks, .mcaddon – add-on packages, .mcgame – player data backups, .mcmeta – resource pack configs, .mcpack – part of an add-on.