Learning how to format an external hard drive Mac is essential. This is a frequent question asked by first-time, as well as the not-so-tech-savvy, macOS users. 'How to format an external hard drive Mac? What format system to use when reformatting my storage drive for a Mac?' If your external drive manufacturer provides such an app, it’s the best option as the solution is cross platform and you can use the password protection feature on both the OS (Windows and Mac). Some of the popular external hard drive manufacturers like Sony, WD, Seagate or SanDisk provide native password protection apps for both Mac and Windows. Compare portable, USB and external hard drive models for office and home and shop online. Discover the world of external hard drives for Mac.