Duplicati is a free, open-source backup client for macOS (and other platforms) that encrypts your files locally before sending them to a wide range of cloud storage providers, network shares, or local destinations.
What is Duplicati?
Duplicati is an open-source, client-side-encrypted backup tool that lets you schedule automatic backups to dozens of storage targets — from Backblaze B2 and Amazon S3 to Google Drive, SFTP servers, and even a plain old external drive. The key architectural decision that sets it apart: encryption happens on your machine before a single byte leaves it. Your cloud provider never sees your data in plaintext.
I've been running it quietly in the background for weeks now, pointed at a B2 bucket, and it has never missed a scheduled run. It's the kind of software that makes you feel better about your digital life without demanding much attention day-to-day.
What does Duplicati do best?
Duplicati excels at confidential, incremental cloud backups — the kind where you trust the encryption math more than you trust the cloud provider's promises. Rather than shipping full archives every time, it performs block-level deduplication and compression, so after the first run your daily increments are tiny and fast. Over a month of daily backups to B2 I've found the ongoing transfer sizes are often under 50 MB for a working dev folder that would be several gigabytes undeduped.
- AES-256 client-side encryption — keys stay local; the server holds ciphertext only.
- 30+ storage backends — S3, Backblaze B2, Google Drive, OneDrive, SFTP, WebDAV, Rclone, local paths, and more.
- Granular scheduling — daily, hourly, on network connect, or manually triggered from the web UI.
- Retention policies — keep the last N backups, keep one per week for a month, or write your own retention expression.
- Restore by date — browse any previous backup snapshot and pull individual files or whole directories.
Is Duplicati free?
Yes — Duplicati is completely free to download and use, including for commercial purposes. It is open-source software released under the MIT / LGPL licence and maintained by a community of contributors on GitHub. The only costs you will encounter are whatever your chosen storage backend charges for space and bandwidth (Backblaze B2, for instance, gives a generous free tier and then charges fractions of a cent per GB after that).
Who should use Duplicati?
Duplicati is best suited to users who are comfortable with a web-based configuration interface and want fine-grained control over where their data lands and how it's protected. It's particularly appealing to developers, sysadmins, and privacy-minded power users who want to verify their encryption setup rather than hand that responsibility off to a commercial app.
If you're looking for a Time Machine-style "just works" experience with a polished native Mac interface, you may find the browser-based UI a little utilitarian. In that case, something like Arq Backup or Carbon Copy Cloner might feel more at home on macOS. But if you want control, auditability, and zero vendor lock-in, Duplicati delivers. I'd also single it out for anyone self-hosting a NAS or small server — its SFTP and WebDAV support means you can back up to your own hardware with the same encryption guarantees as a public cloud.
How does Duplicati compare to Arq Backup?
Arq Backup is the polished commercial alternative most often mentioned in the same breath as Duplicati. Arq has a genuinely native macOS interface, tight Spotlight and menu-bar integration, and a one-time or subscription purchase model. Duplicati counters with a zero cost, a broader backend library, and fully open source code you can inspect and self-host. Arq is the choice if you want a Mac citizen; Duplicati is the choice if you want maximum transparency and portability. Both encrypt client-side. Neither is obviously superior — it really comes down to whether you value polish or openness more.
On the free-vs-free front, Time Machine is the obvious comparison. Time Machine is simpler and baked into macOS, but it only targets Apple-blessed local disks and Time Capsules. Duplicati reaches anywhere a URL can point.
What are the best Duplicati alternatives?
Beyond Arq and Time Machine, the field includes Restic (powerful CLI-first tool, also open-source and encrypted, but no GUI), Rclone (sync rather than true backup, but Duplicati can actually use it as a backend), Carbon Copy Cloner (bootable local clones, not cloud-oriented), and Backblaze Personal Backup (unlimited cloud backup as a subscription, but proprietary and US-only). For pure cloud-to-cloud or enterprise needs, Veeam enters the picture. Duplicati sits in a sweet spot: richer than Restic for non-CLI users, freer than Arq, and more flexible than Backblaze's consumer product.
