Syncthing: when to install it, and when not to
Keeping two machines in agreement without a central service or an account. Open source, and it solves the everyday problem of working on more than one…
The short version
Syncthing: 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.
| Licence / price | Free · Open source |
|---|---|
| Platforms | Windows, macOS, Linux, Android |
| Category | Backup & Sync — 5 programs |
| Official download | https://syncthing.net/downloads/ ↗ |
What it is for
Keeping two machines in agreement without a central service or an account. Open source, and it solves the everyday problem of working on more than one computer.
When to pick something else
It is synchronisation, not versioned backup. Delete a file on one machine and the deletion reaches the other within seconds. For accidental deletion or ransomware you need Duplicati or Restic as well.
How it compares in Backup & Sync
These are the alternatives we would consider for the same job. The notes are the same ones used on the main list, so there is no separate ranking hiding on this page.
| Program | Licence / price | Platforms | Why it is on the list |
|---|---|---|---|
| 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. |
Practical notes
- Enable file versioning on the folder even if you also run a separate backup.
- Keep one copy on a device that is not always mounted and always reachable from the machine.
Questions people ask
Is a sync folder a backup?
No. That distinction is the single most common mistake in this category.
Where it appears in our guides
- Setting up a new Windows PC: the order that actually works
- Before and after a clean reinstall: the checklist
- A backup you can actually restore
- Do you need a third-party antivirus on Windows 11?
- Moving off browser-saved passwords in one sitting
See the full Backup & Sync explainer for the other 4 programs in this category.
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.