Syncthing

What is Syncthing?

Syncthing synchronizes files directly between two or more computers in real time, with no central server involved. Data never touches third-party infrastructure, and everything is protected by TLS. A strong replacement for Dropbox-style sync without the cloud.

Best for

Keeping folders in sync across devices privately

Why choose Syncthing

Syncthing is the most trustworthy file-sync tool available, largely because of how little it asks you to trust. There is no central server, no account and no company in the middle: devices find each other, establish encrypted connections and synchronise directly, with every device holding the same data. That architecture means there is no service to go down, no storage quota, and no party that could read your files even if it wanted to.

Replaces

• Dropbox
• Resilio Sync
• Google Drive

Key features

• Peer-to-peer sync
• No central server
• TLS encryption
• Cross-platform

What to watch out for

Peer-to-peer synchronisation has consequences worth understanding. It is not a backup: a deletion on one device propagates as a deletion everywhere, and a file that is corrupted locally will be faithfully replicated. Continuous sync uses storage and bandwidth on every participating device, which matters on phones, and very large or numerous files can be slow to reach a first synchronisation. Conflict handling, when two devices edit the same file offline, produces duplicate copies with a conflict suffix rather than a merge.

How to deploy

• Binary
• Docker
• Package managers

Getting started

Install on two devices first and pair them by device ID, confirming one small folder synchronises before adding your real data. Set up versioning on at least one device — staggered or trash-can style — because that is what turns an accidental deletion from a disaster into an inconvenience. Put a separate real backup in place as well; the common mistake is believing that a synchronised copy is a safe copy. Turn off sync on metered connections for mobile clients, or the first large folder will surprise someone with a phone bill.

Typical setup

It runs on every device that needs the data — desktop, laptop, phone, server — and pairs them directly. People commonly designate one always-on machine as the long-lived copy and add genuine backups on top of it, since synchronisation is not backup. Mobile clients are usually set to sync only on Wi-Fi, and versioning is enabled on at least one device so that a mistaken deletion can be recovered rather than propagated to everything.

Who should look elsewhere

Not a backup, and treating it as one is the most common and most costly mistake with this tool. A deletion or a corruption propagates by design. It is also a poor fit for very large media libraries where continuous syncing would consume storage and bandwidth on every device, and for anyone who wants a central authoritative copy rather than a peer network.

Project health

• GitHub stars: 89,064
• Last code push: 2026-09-30
• Open issues: 386
• Status: actively developed

Figures pulled from the GitHub API and refreshed periodically.