Techtool Pro 9.6.1 and later support High Sierra, along with its new file system, APFS. The support for APFS initially will focus on testing and repairing the file system. More in-depth features, such as optimizations, are still under development. The future availability of these features will depend on Apple releasing a more complete set of documentation detailing the inner workings of APFS. All other tests and tools are tested as fully compatible with High Sierra.