15+ external SSDs were evaluated, with manufacturer specs, expert benchmarks, and user reviews compared to find the best external SSDs for Mac users. An external SSD for Mac is a portable solid-state drive that connects via Thunderbolt or USB-C and works natively with macOS, offering read speeds between 1,000-2,800 MB/s for Time Machine backups, photo libraries, and video editing. Choosing the right external SSD for your Mac is harder than it looks.