Syncthing – continuous file synchronization program

Syncthing is a continuous file synchronization application that keeps directories aligned across multiple computers. It exchanges files directly between devices rather than requiring users to upload their data to a conventional cloud storage provider.

Every device has a unique cryptographic identity. Users choose which devices to trust and which folders to share, with synchronization taking place automatically as files are created, modified or deleted. Discovery and relay services help establish connections when machines cannot communicate directly.

Syncthing uses a block-based transfer protocol, allowing devices to exchange changed portions of files instead of repeatedly transferring entire files. It is particularly useful for maintaining personal document collections, sharing folders between workstations and synchronizing data across a home network.

Its interface is accessed through a web browser, while the synchronization engine runs independently in the background.

This is free and open source software.

Key Features

• Continuous synchronization between computers across local networks and the internet.
• Supports send-and-receive, send-only and receive-only folder configurations.
• Encrypts connections using TLS and authenticates devices with cryptographic certificates.
• Global discovery, local discovery, NAT traversal and relay servers help establish connections between devices.
• File versioning options allow older copies of modified or deleted files to be retained.
• Supports encrypted folders on untrusted devices, keeping file contents and names inaccessible to the remote system. This facility remains experimental.
• Detects filesystem changes automatically and schedules rescans where necessary.
• Allows files and directories to be excluded through configurable ignore patterns.
• Detects conflicting modifications and preserves conflict copies for inspection.
• Provides a browser-based management interface and REST API for configuration and automation.
• Supports synchronizing file permissions, symbolic links and extended attributes where compatible with the underlying systems.
• Uses an SQLite database for file indexes and synchronization metadata.
• Structured logging with configurable log levels helps diagnose synchronization problems.
• Cross-platform support – runs on Linux, Windows, macOS and several other operating systems.

Website: syncthing.net
Support:
Developer: Many contributors
License: Mozilla Public License v2.0

Syncthing is written in Go. Learn Go with our recommended free books and free tutorials.

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