Arq review: Offers an archiving alternative to Time Machine and hosted cloud backup services

Your passphrase is stored in Keychain and accessed by Arq and its background agent as needed. You can unlock Keychain with your login password to view Arq passphrases. So long as you can recover your passphrases if your computer or startup drive were lost, stolen, or destroyed, you can restore the corresponding Arq backups. Lose the passphrases, though, and your backup is locked away forever.

The only vulnerability here is while your Mac is running, someone who could gain access to an active session on your computer could potentially grab your encryption keys. That’s a risk with all locally controlled encryption, however, and not unique to Arq. And having all the keys decrypted only locally, never transmitted and never used on remote servers, vastly reduces the potential of them being obtained.

Comparing with Time Machine, CrashPlan, and ChronoSync

The real test of Arq is whether it fits users’ needs where other backup software and services fall short.

Time Machine. I don’t have to recount to most people the troubles with Time Machine. While it has grown increasingly reliable, release after release, it’s not configurable. And when a backup fails, it often corrupts silently and with little recourse. Time Capsule is even worse, in that you can’t access the drive directly, and many people have written me about an entire Mac’s worth of Time Machine backups being flushed from Time Capsule.

Several third-party Time Machine utilities that let you control its function better have fallen by the wayside, and it’s now difficult to impossible to choose specific folders or files to backup, set a schedule, or control archive depth.

Time Machine also omits encryption. If your Time Machine target is an encrypted volume, it’s secure at rest (unmounted), but files are written in the clear. Finally, Time Machine only backs up to local drives and networked volumes.

CrashPlan. CrashPlan should be a viable alternative, based on features. CrashPlan lets people backup at no cost locally or to a networked or peer’s Mac or Windows system running a CrashPlan client. It also lets you pick your own encryption key (in two different variants), controlling ownership of your encryption. It offers great file and folder selection. Its flat-rate unlimited cloud backup is reasonably price for individuals and families.

However, the CrashPlan Java client for home users is a sticking point. It’s not reliable, fast, or easy to use, although its restore feature is far superior to the current state of Arq’s restore. Mac users shouldn’t install or use Java, even in the restricted form that’s packaged with CrashPlan.

CrashPlan also backs up to a proprietary format, even locally, and can’t pick other cloud destinations.

ChronoSync. ChronoSync combines some of the best options of cloning software and Time Machine, and has many similar advantages to Arq. However, its complexity best maps to those who really need to dig into the options and learn them. You can create extraordinary layers of archives and exclusions and schedules. It’s definitely over the top for average users, even when you try to choose the kind of sync option from a popup menu. I’m very glad the app exists, but I can’t recommend it broadly.

ChronoSync also isn’t built around encryption. The only option to use encryption is with Amazon S3 and Google Cloud Storage, and only using limited server-side options that I don’t recommend.

The app is best for people who have very specific and sometimes elaborate needs.

Bottom line

Arq seems to hit several sweet spots for folks who want to own their encryption fully and control more of their backup process, including having identical or different local and cloud archives.

The initial setup isn’t painful, and there’s so little configuration, I can recommend it to users who feel overwhelmed with some of the competing options. Its ability to work with Dropbox and Amazon Cloud Backup provide reasonable alternatives to other cloud-based backup services.

If Arq seems too thin to you, I recommend ChronoSync, which offers a staggering array of options and customization. But for most people, Arq should provide the right combination of power, simplicity, one-time cost, and ongoing hosted data costs.