Syncthing vs Unison (2026): which should you pick?
As of Nov 13, 2026, Syncthing and Unison share a 2.6 GPA, both are free, so the choice depends on which features you need.
Checked Oct 5, 2026 and Nov 13, 2026 · graded Oct 10, 2026 and Nov 13, 2026 by ToolGPA
They get the same grade on all five counts.
Price, platforms and features side by side. The table says where each price was read and when.
Unison
Open-source two-way file synchronizer for Unix, macOS and Windows
Free
Which one is for you
Pick Syncthing if
- Fits if you want folders in step between your own computers with no cloud provider involved
- Works for people with a home server who want a desktop's folders copied to it
Look elsewhere if
- Skip it if you want your files on your iPhone, as there are no plans for an official iOS app
- Not for you if you want a cloud copy, since files live only on your own devices
- Not for you if a command-line program with a browser settings page sounds like hard work
- Watch out: devices swap files only when both are online at the same time
- Watch out: there are no sharing links, and help is a community forum unless you pay Kastelo, a separate company
Pick Unison if
- Fits if you are happy in a terminal and want conflict-aware sync between two machines
- Works for people syncing a laptop with a Unix server over ssh
Look elsewhere if
- Skip it if you want a point-and-click app, as it is run from the command line
- Watch out: the project releases source, and pre-built binaries come from other sources
- Tight if you need help: the README says not to ask in GitHub issues
- Watch out: the maintainers say very few people work on it, so fixes are slow
- Not for you if you want cloud storage sync, as it is two-folder sync
How we grade them
| 2.6GPASyncthingGood | 2.6GPAUnisonGood | |
|---|---|---|
| Value for money | AFree software with no paid plans at all, where the rest of this category charges around $5 a month for ever. The project lives on donations, and if you want somebody to call, a separate company, Kastelo, sells commercial support. | AFree under the GPL-3.0 licence, with no paid editions. Anyone can download and run it. |
| Free plan and trial | AFree outright on every operating system it supports, source code and all, with no paid tier above it holding anything back and no account to make in the first place. | AThe whole program is free with no limits, and you only need the two places to sync. |
| Features | CIt does its one job completely: continuous sync of as many folders as you like, over encrypted and authenticated connections, at home or across the internet. But that one job is smaller than this category's. There's no cloud copy, no sharing links, and devices swap files only when both are online. | CTwo-way sync, conflict detection, rsync-style transfers and repeat mode. It does that one job fully, and it is a smaller job: no cloud services or mobile. |
| Ease of use | DWhat you download is a command-line daemon you configure through a page in your browser, on every machine, with tray icons and file-browser integration as separate downloads. Devices do pair by ID with no network fiddling, but this is not install and go. | DA command-line program released as source, with pre-built binaries from packaging systems. Help comes from a wiki and mailing lists. |
| Platforms and integrations | CComputers only: Mac, Windows, Linux and several BSD systems. No phone apps are listed and the team says it has no plans to support iOS officially, so your photos and your phone are out of the picture. | CA program for computers alone: Mac, Windows and Linux. No phone, web or cloud integrations are listed. |
| Best for | syncing your own computers with no cloud | two-way file sync, free and open source |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: Syncthing and Unison. How we grade
Price against what you get
Syncthing has no paid plan and scores 1.7 out of 4 on features, ease of use and platforms. Unison has no paid plan and scores 1.7.
On this chart the two sit in the same place: the same score for the same starting price. Of the other file storage and sync services on the chart, none scores higher than Syncthing for less, and none scores higher than Unison for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
In commonFree planmacOSWindowsLinuxOpen sourceFile sync
At a glance
| Syncthing | Unison | |
|---|---|---|
| Pricing | Free | Free |
| Starts at | Free | Free |
| Free plan | Syncthing is free software with no paid plans. The project's servers and development grants are funded by donations. | None |
| Free trial | None listed | None listed |
| macOS | ||
| Windows | ||
| Linux | ||
| Made by | The Syncthing Foundation | Unison open-source project |
| Price read from | syncthing.net | github.com |
| Checked | Oct 5, 2026 | Nov 13, 2026 |
Worth knowing
Syncthing
- There is no cloud storage: files live only on your devices, and devices exchange data only when they are online at the same time.
- The Syncthing team says it has no plans to officially support iOS; a separate open source iOS app incorporates Syncthing.
- The base download is a command-line daemon with a web interface. Tray icons and file browser integration come from separate downloads.
- Support is through the community forum; commercial support is sold by a separate company, Kastelo.
Unison
- The project releases source code; pre-built binaries come from packaging systems or CI builds.
- The README says not to ask for help in GitHub issues; questions go to the wiki and mailing lists.
- The maintainers say very few people work on it, so bug and feature handling is slow.
- The old project website is archival; development and issues are on GitHub.
Key features
Syncthing
- Continuous synchronization
- Folders are kept in sync between two or more computers in real time. You can sync as many folders as you need, with other people or only between your own devices.
- No central server
- Data is never stored anywhere other than on your own computers, so there is no cloud account or third-party server holding the files.
- Encrypted, authenticated connections
- All communication is secured with TLS and perfect forward secrecy. Each device has a cryptographic certificate, and only devices you explicitly allow can connect.
- Browser-based interface
- Syncthing is configured and monitored through a responsive web interface served by the program and opened in a browser.
- Works over LAN and Internet
- Devices find each other by ID without IP addresses or advanced configuration. UPnP is used where available, and relays carry traffic when no direct connection is possible.
- Open protocol and source
- The sync protocol is a documented specification and all source code is public, with development and bug reports open for anyone to read.
Unison
- Two-way synchronization
- Changes made on either replica are propagated to the other, and updates that do not conflict are applied automatically.
- Conflict detection
- When both sides changed the same file, Unison shows the conflict instead of silently picking a winner.
- Cross-platform pairs
- It can synchronize a Windows laptop with a Unix server, for example, over ssh or directly over TCP.
- Efficient transfers
- Small edits to large files use a compression protocol similar to rsync's, which suits slow links.
- Repeat mode
- With a filesystem monitor, repeat mode propagates changes soon after they happen.
- No special privileges
- It is a user-level program: no kernel changes, superuser rights or FUSE are needed on either host.
Plans
Syncthing
SyncthingFree
The full program for every supported operating system, with source code available on GitHub.
Unison
Free$0
Full source code under the GNU General Public License, version 3; there are no paid editions.
Common questions
Which is cheaper, Syncthing or Unison?
As of Nov 13, 2026, both Syncthing and Unison are free to use.
Which has a free plan, Syncthing or Unison?
As of Nov 13, 2026, both Syncthing and Unison have a free plan.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.