Syncthing is a continuous file synchronization program. It synchronizes files between two or more computers in real time, safely protected from prying eyes. This means the creation, modification or deletion of files on one machine will automatically be replicated to your other devices.
It uses the Block Exchange Protocol v1 (an open and documented protocol) to exchange file data and metadata between Syncthing devices. Syncthing segments files into pieces, called blocks, to transfer data from one device to another. Therefore, multiple devices can share the synchronization load, in a similar way to the torrent protocol.
File contents and file modification times are always synchronized. File permissions, symbolic links, file or directory owners and groups, extended attributes, and POSIX or NFS ACLs may be synchronized.
This is free and open source software.
Key Features
- Private – no data is ever stored anywhere else other than on your computers. There is no central server that might be compromised.
- Encrypted – all communication is secured using TLS. The encryption used includes perfect forward secrecy to prevent any eavesdropper from ever gaining access to your data.
- Authenticated – each device is identified by a strong cryptographic certificate. Only devices you have explicitly allowed can connect to your other devices.
- Powerful – synchronize as many folders as you need with different people or just between your own devices.
- Simple to use – doesn’t need IP addresses or advanced configuration: it just works, over LAN and over the Internet. Every machine is identified by an ID
- Cross-platform support – runs under Linux, FreeBSD, OpenBSD, Solaris, macOS, Windows, and other operating systems.
Website: syncthing.net
Support: GitHub Code Repository
Developer: Many contributors
License: Mozilla Public License 2.0

Syncthing is written in Go. Learn Go with our recommended free books and free tutorials.
Related Software
| File Synchronization Tools | |
|---|---|
| Syncthing | Continuous file synchronization program |
| Unison | File-synchronization tool for POSIX-compliant systems |
| Rclone | Command line program to sync files and directories |
| rsync | Fast incremental file transfer |
| Cryptomator | Multi-platform transparent client-side encryption of files in the cloud |
| FreeFileSync | Folder comparison and synchronization software |
| syncBackup | Backup and mirror your drives |
| Seafile | Coud storage system with privacy protection and teamwork features |
| Grsync | Graphical user interface for rsync |
| Lsyncd | Live Syncing Daemon |
| luckyBackup | Backup & sync tool |
| YARsync | Yet Another Rsync |
| Sync-in | File sync and server management |
| osync | Two way filesync script running on Bash |
| Celeste | GUI file synchronization client |
| ByteSync | File synchronization, backup, and deduplication |
| bita | Differential file synchronization over HTTP |
| Spacedrive | File manager powered by a virtual distributed filesystem |
Read our verdict in the software roundup.
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