Pros
Cons
Our Verdict
When I last reviewed ChronoSync (version 3.3, in 2008) it was already a mature, full-featured utility for synchronizing files and folders between volumes or computers. In the years since, ChronoSync has become even more powerful, extending its backup and network synchronization capabilities.
The basic program layout remains the same: You choose one folder or volume on the left side of the window and another on the right, select your options, and click Synchronize to copy your data. You can customize this simple-sounding procedure in a vast number of ways. For example, you can copy in either direction or bidirectionally, synchronize deletions in either direction, archive changed and deleted files, create rules to include or exclude files matching any pattern you describe (such as those files under a certain size or having a particular Finder label), and so on. You can also click a Trial Synchronization button to display the results of the synchronization without copying any data. ChronoSync can take any of numerous actions in the event of a sync conflict—for example, always overwrite in one direction or the other, always choose the older or newer file, skip the file altogether, or prompt you to choose one or the other manually.
Generally ChronoSync does a good job of keeping its interface simple for basic operations while offering more-complex options for users who need greater control. However, some operations that are simple in other backup programs may seem strangely complicated here. For instance, you can’t see a hierarchical list of an entire volume and merely check or uncheck the items you want to sync or back up. If you wish to select or deselect several arbitrary files or folders, you would typically create a separate synchronization document (which holds all the settings for a given operation) for each one. You can group these documents into containers to run several of them at once, but if you frequently change your selection of files and folders, you may find the process to be cumbersome.
ChronoSync 4.3.5 supports the copying of all essential metadata, ownership, and permissions, and it can make a bootable duplicate of an entire startup disk. ChronoSync could already create versioned backups (retaining older and deleted versions of backed-up files), so it’s now just as capable as an all-purpose backup tool as it is for synchronization.
When it comes to restoring backups, ChronoSync does have a limitation compared to Time Machine (and many other backup apps). Although you can select any version of any backed-up file or folder and restore it to its original location or somewhere else, you get no view in which you can see all your files as they looked at some arbitrary time in the past. If you want to restore many files from a variety of locations or restore an entire volume to a state earlier than its most recent backup, the procedure will involve a long series of manual steps.
The program offers tremendous flexibility for scheduling synchronization and backup operations. You can choose a repeating schedule (such as every minute or every three weeks), any number of arbitrary dates and times, or whenever certain trigger events occur, such as a volume mounting. On each run, ChronoSync copies only the items that have changed since the previous run, and you can select any of more than a dozen criteria to determine what should count as a change. I would like to see ChronoSync go one step further and offer an option found in some other sync software: the ability to watch specified folders and synchronize changes as soon as they occur rather than waiting until the next scheduled run.
ChronoSync can use any network volume mounted in the Finder as a source or destination. However, if you need to preserve ownership and permissions when copying files over a network (especially important when copying items outside your home folder), you can install an optional companion program called ChronoAgent 1.3.6 ($10) on another Mac. This utility gives ChronoSync, running on your Mac, complete administrator access to the files on the other Mac and improves file copying performance. ChronoAgent also enables ChronoSync to perform the neat trick of creating a bootable duplicate over your network. (Only three other apps— Carbon Copy Cloner, Retrospect, and Synk—have this capability.) With ChronoAgent installed on another Mac, ChronoSync can initiate a backup automatically whenever that Mac appears on your network, and the program can wake up the remote Mac when it’s time for a scheduled backup.
Bottom line
ChronoSync 4.3.5 exhibited excellent performance in my testing. With a bit of configuration, it can fill almost any synchronization or backup need, and the added capabilities of ChronoAgent make it that much more compelling. If you’re looking for a single app to handle synchronization and backup tasks, ChronoSync is an impressive choice.