Syncthing: Real-Time File Synchronization Without the Cloud, the Ads, or the Surveillance
What Is It?
Syncthing is a peer-to-peer synchronization tool that replaces cloud-based solutions like Dropbox or OneDrive — but without centralized servers, subscriptions, or data leaks. Every device runs its own instance, and files sync directly between them using strong encryption, versioning, and conflict detection. It works cross-platform and can sync in real time over LAN or the internet.
Sysadmins love it for syncing config files, toolkits, or backups between machines. Developers use it for sharing code or documents without Git. And power users run it on everything — from laptops to NAS boxes and even Raspberry Pi — because it just works, quietly and privately.
Capabilities
| Feature | Description |
| Peer-to-Peer Sync | Devices talk directly — no central server needed |
| Cross-Platform | Runs on Windows, Linux, macOS, BSD, Android, Docker, and more |
| Encrypted by Design | All communication is secured with TLS and device IDs |
| Versioning Support | Keeps old versions of files if changes conflict or are deleted |
| Selective Sync | Choose which folders or subfolders to sync on each device |
| Web-Based UI | Configure everything via local browser interface (default: port 8384) |
| Portable & Headless Options | Runs as a background service or GUI, even on headless devices |
Deployment Notes
– Requires port forwarding or relay for devices outside local network.
– Resource-light, but disk I/O can spike during large sync operations.
– Uses its own sync protocol, not rsync or SMB — fully encrypted and efficient.
– No user accounts or logins — devices authenticate via shared IDs and keys.
– Works great in closed networks, even without internet (LAN-only mode).
Installation Guide
1. Download from Official Site
– https://syncthing.net (choose package for OS)
2. Install or Run as Portable
– Extract or install depending on OS; no root/admin needed in most cases.
3. Access Web GUI
– Open http://localhost:8384 in browser.
4. Add Remote Devices
– Exchange device IDs and approve connections.
5. Create Shared Folder
– Choose path, folder ID, sync options, and which devices participate.
6. Set Versioning Rules (Optional)
– Enable trash, staggered versions, or simple file history.
Usage Scenarios
– Syncing working directories between a desktop and a laptop automatically.
– Distributing scripts, configs, or toolkits across a fleet of internal machines.
– Running private sync between mobile devices and desktops without using cloud services.
– Backing up critical folders to multiple machines for redundancy.
– Sharing files securely in small teams or air-gapped environments.