Backup & Sync: what to install, and why
A backup you have never restored is a hope, not a backup. This category is deliberately small because the hard part is not choosing software, it is…
What this category is for
A backup you have never restored is a hope, not a backup. This category is deliberately small because the hard part is not choosing software, it is deciding what needs to survive, where the second copy lives, and proving once that you can get it back.
What we filter on
- A documented restore path, not just a convenient sync direction.
- Supports a copy that is not on the same machine and not always mounted, so ransomware cannot reach it.
- No proprietary format that requires the vendor to be online to recover a file.
- Honest about what it is: synchronisation is not versioned backup.
The 5 programs, compared
The table below is generated from the same directory data as the main list. Licence wording matters here: free for personal use is not the same as free for a work machine, and source-available is not the same as open source. Every link opens the publisher's own site.
| Program | Licence / price | Platforms | Why it is on the list |
|---|---|---|---|
| Syncthing Publisher's site ↗ | Free · Open source | Windows, macOS, Linux, Android | Keeps folders identical across your own devices, peer to peer, with no cloud in the middle and no account. Because deletions propagate, it is synchronisation rather than backup. Pair it with versioning turned on. |
| FreeFileSync Publisher's site ↗ | Free · Open source | Windows, macOS, Linux | Compares two folders and shows you exactly what will be copied, moved or deleted before anything happens, then does it and verifies the result. The clearest free tool for mirroring to an external drive. |
| Duplicati Publisher's site ↗ | Free · Open source | Windows, macOS, Linux | Scheduled encrypted incremental backups to a local drive, a NAS or cloud storage, with a browser interface and retention rules. Good for a home setup. Test a restore before you trust it with anything. |
| Restic Publisher's site ↗ | Free · Open source | Windows, macOS, Linux | A single command line binary that does fast, encrypted, deduplicated snapshots to almost any storage backend. The choice for people who want backups they can script and verify rather than click through. |
| Backblaze Personal Backup Publisher's site ↗ | Paid · From $99/year | Windows, macOS | Unlimited cloud backup of one computer for a flat annual fee, including external drives. The one paid subscription on this page that most households should genuinely consider, because off-site is the part people skip. Free 15-minute restore window for the first 30 days. |
If you only install one
Syncthing. It keeps two machines in agreement without a central service or an account, and it is open source. That solves the everyday problem of working on more than one computer. It does not solve the I deleted a file three weeks ago problem, which is why the table below separates sync from versioned backup.
Its Free · Open source licence and Windows, macOS, Linux, Android support are listed in the table above. The rest of this category exists because the right answer changes with the job, not because the other entries are filler.
The trade-offs
| Instead | What changes |
|---|---|
| FreeFileSync | One-shot folder comparison and copy, easier to reason about than a continuous daemon if you prefer to decide when copies happen. |
| Duplicati / Restic | Versioned, encrypted backups with history. More setup, but they are the actual answer to accidental deletion and ransomware. |
| Backblaze | The only paid entry here. It is an off-site copy that runs without you remembering to plug in a drive; the annual fee buys that convenience. |
Mistakes we see
- Calling a sync folder a backup. Delete a file on one machine and the deletion propagates to the other within seconds.
- Keeping the only second copy on an external drive that is permanently plugged in and always mounted.
- Never testing a restore. Run one small restore the day you set the backup up, then you know the passphrase, the tool and the location all work.
Questions people ask
What is the simplest setup that actually works?
One local versioned backup to an external drive, plus one off-site copy of the files you cannot replace. Two copies, one of them away from the machine.
Is cloud sync enough?
It protects against a dead laptop. It does not reliably protect against deletion, corruption or a compromised account unless versioning is enabled.
Where to go next
These guides use tools from this category:
- Setting up a new Windows PC: the order that actually works
- Before and after a clean reinstall: the checklist
- Building a reliable remote-work machine
- A backup you can actually restore
Or continue through the other categories:
- Browsers — 4 programs
- Files & Organisation — 6 programs
- Media, Recording & Capture — 10 programs
- Graphics & Design — 7 programs
- Documents & Notes — 8 programs
- Communication — 6 programs
- Privacy & Security — 10 programs
- Developer Tools — 12 programs
- System & Hardware — 8 programs
- Network & Remote — 6 programs
How to read this page. How to read this page. Platform, licence and publisher details come from our directory data. Where an independent review, audit or survey is mentioned, it is summarised in our own words with the source named and linked; our /sources page sets out that policy. The recommendation, the trade-offs and every 'skip it if' line are our editorial judgement. We do not run benchmarks, publish measured performance figures or host installers, and every download link goes to the publisher's own site. If a detail is out of date, our About page explains how to tell us.