What are some alternatives?
When comparing ChronoSync and Carbon Copy Cloner, you can also consider the following products
Time Machine - Time Machine is the breakthrough automatic backup that’s built right into Mac OS X.
Acronis True Image - Compare Acronis True Image 2018, True Image Premium, and other online and cloud backup solutions. Find the best backup software for your needs.
Duplicati - Free backup software to store backups online with strong encryption. Works with FTP, SSH, WebDAV, OneDrive, Amazon S3, Google Drive and many others.
Clonezilla - Clonezilla is a suite of software that's designed to allow you to back-up and image new hard drives with your data.
SpiderOak - SpiderOak makes it possible for you to privately store, sync, share & access your data from everywhere.
SuperDuper! - Have no fear. SuperDuper v3. 1. 1 is here, and it includes full High Sierra HFS+ and APFS support! SuperDuper is the wildly acclaimed program that makes recovery painless, because it makes creating a fully bootable backup painless.