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ProductivityAlternative to DropboxAlternative to Resilio Sync

Syncthing

Continuous, decentralized file synchronization program for private cross-device sync.

View on GitHub Visit website
LicenseMPL-2.0
GitHub stars87.9k
Last commit1 weeks ago
Tags6 topics
BackupP2pPrivacyDecentralizedFile SyncGolang
Overview

Why consider Syncthing?

Syncthing synchronizes files continuously across multiple devices without storing data on central third-party servers. It uses peer-to-peer TLS encryption and block-level transfer.

Guided learning

Learn Syncthing by building

Practical setup notes, real use cases, and copy-ready examples in one focused guide.

4 min read 11 sections
In this guide11 sections

What is Syncthing?

Syncthing is an open-source, peer-to-peer file synchronization application written in Go that acts as a decentralized alternative to commercial cloud storage services like Dropbox and Resilio Sync. It synchronizes files in real time between two or more computers over local networks or the internet without transmitting or storing data on central third-party servers.

Communication in Syncthing is secured via TLS with cryptographic device certificates, ensuring that only explicitly paired devices can discover and exchange file blocks.

Who Is It For?

  • Home Lab Enthusiasts & Homelabbers: Synchronizing media libraries, documents, and backups between laptops, desktop workstations, and network-attached storage (NAS).
  • Developers: Mirroring configuration dotfiles, project assets, and local documentation between personal and work machines without using cloud storage buckets.
  • Privacy Advocates: Keeping sensitive financial records, passwords, and private photos strictly on personal hardware without cloud leaks.

Key Features

  • Decentralized peer-to-peer architecture with no central database or mandatory cloud account.
  • Block-level incremental delta transfers so only modified parts of large files are transmitted.
  • Cross-platform support across Linux, macOS, Windows, Android, FreeBSD, and Docker.
  • Comprehensive web-based administration interface with live bandwidth monitoring.
  • Granular folder controls including Send Only, Receive Only, and file versioning (Staggered, Trash Can, Simple).

Installation and Quick Start

You can install Syncthing via system package managers or deploy it as a persistent Docker service.

Using Docker Compose:

yaml
1version: '3'
2
3services:
4 syncthing:
5 image: syncthing/syncthing:latest
6 container_name: syncthing
7 hostname: my-syncthing
8 environment:
9 - PUID=1000
10 - PGID=1000
11 volumes:
12 - ./config:/var/syncthing/config
13 - ./data:/var/syncthing/Sync
14 ports:
15 - 8384:8384 # Web GUI
16 - 22000:22000/tcp # Sync protocol
17 - 22000:22000/udp # Sync protocol
18 - 21027:21027/udp # Local discovery
19 restart: unless-stopped

Start the container:

bash
1docker compose up -d

Access the Web GUI by navigating to http://localhost:8384 in your web browser.

Step-by-Step Device Pairing Workflow

  1. Open the Web GUI on Device A and click Actions -> Show ID to view the alphanumeric Device ID and QR code.
  2. Open the Web GUI on Device B, click Add Remote Device, paste Device A's ID, and assign it a recognizable name.
  3. Switch back to Device A to accept the incoming pairing request.
  4. Click Add Folder on either device, specify the local path, and check the paired device in the Sharing tab to initiate automatic bidirectional synchronization.

Practical Use Cases

1. Multi-Device Photo and Document Backup

A user configures an Android smartphone to automatically sync camera photos to a home Linux server over Wi-Fi whenever the phone connects to the local home network.

2. Obsidian Notes Synchronization

A writer maintains a local folder of Markdown notes and uses Syncthing to synchronize edits across a macOS laptop, a Windows desktop, and a Linux server with zero cloud latency.

3. Server Configuration Deployment

A system administrator distributes application configuration files and static site assets to multiple edge nodes using a "Send Only" folder topology.

Troubleshooting and Limitations

  • Inotify Limits on Linux: When syncing large folders with tens of thousands of files, increase the kernel file watch limit via sysctl fs.inotify.max_user_watches=204800.
  • Concurrent File Conflicts: If two devices modify the same file simultaneously while offline, Syncthing generates a conflict file with a timestamp suffix (.sync-conflict-...) rather than overwriting data.

Official Resources

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Syncthing FAQs

Syncthing is listed as a Productivity tool on TiloBox. Review the overview, features, and official documentation on this page to decide whether it solves your specific workflow.

Start with the project's GitHub repository and official website for supported installation and deployment instructions. Test the setup with representative data or a small project before rolling it out more widely.

Syncthing is listed under the MPL-2.0 license. Read the complete license text and the project's notices before using, modifying, or distributing the software.

Production readiness depends on your requirements. Review maintenance activity, security practices, documentation, backup and upgrade procedures, and compatibility with your stack; then validate it in a non-production environment.

Syncthing is listed as an alternative to Dropbox. Compare the core workflow, deployment model, integrations, and licensing against your must-have requirements before switching.