“One of the purest open-source wins: your folders simply stay in sync across your devices.”
At a glance
| Replaces | Dropbox Sync, Resilio Sync |
|---|---|
| Open-source license | MPL-2.0 |
| Privacy | Encrypted direct device sync; no central file store or service account. |
| Lightweight signal | Small daemon and web UI run on desktops, servers, and low-power devices. |
| Community health | Large, mature and highly trusted project |
| Platforms | Windows, macOS, Linux, Android, BSD |
Encrypted direct device sync; no central file store or service account.
Small daemon and web UI run on desktops, servers, and low-power devices.
Large, mature and highly trusted project. Verify current releases and open issues in the source repository before critical deployment.
Who is Syncthing best for?
Syncthing is most useful for people moving from Resilio Sync, Dropbox Sync, or another cloud-dependent folder-syncing service who want direct device-to-device transfers, unlimited shared folders, and full control over their files without a paid tier.
If you're currently using Resilio Sync (formerly BitTorrent Sync) and looking for a free, open-source replacement, Syncthing is the most direct alternative you'll find. Both tools use peer-to-peer (P2P) syncing — your files go directly between your devices without passing through a central server. But where Resilio Sync moved to a freemium model (with paid plans for more than one folder and selective sync), Syncthing stays 100% free, open source (MIT), and self-contained.
Here's a head-to-head comparison to help you decide whether to switch:
Resilio Sync vs Syncthing
Bottom line: If you only sync one folder and don't mind closed-source, Resilio Sync's free tier might work. But as soon as you need multiple folders, version history, or selective sync — or if you simply prefer fully auditable code — Syncthing wins.
Why switch from Resilio Sync to Syncthing?
Scenario 1: You need to sync more than one folder
Resilio Sync's free tier is limited to a single sync folder. If you want separate folders for work documents, family photos, and a media library, you'd need the Pro plan ($49.99/year). Syncthing handles unlimited folders out of the box, all free.
Scenario 2: You want file versioning without paying
Resilio Sync keeps versioning behind the Pro paywall. Syncthing gives you four versioning strategies (trash can, simple, staggered, external) — all free, all configurable per folder. Accidentally overwrite a critical file? Syncthing's staggered versioning keeps hourly snapshots for the past 24 hours, daily for the past 30 days, and weekly beyond that.
Scenario 3: You value auditable, transparent code
Because Syncthing is open source (MIT), the entire codebase is publicly reviewed. You don't have to trust a company's privacy policy — you can verify exactly what the software does, how it handles your data, and whether it phones home. For privacy-conscious users managing sensitive documents, this transparency isn't optional.
Quick start with Syncthing
If you're coming from Resilio Sync, the setup is similar — but there are a few differences worth noting:
- 01
Install Syncthing — binaries are available for all major platforms. For Linux,
apt install syncthing; macOS users can usebrew install syncthing; Windows has a standard installer. (If you prefer a pre-configured setup, this site's installation script generator can help.) - 02
Add devices — each device gets a unique device ID (a cryptographic fingerprint). Add your other devices by pasting their IDs into the web UI; no account, email, or cloud relay required.
- 03
Share folders — right-click a folder in the UI and share it to one or more connected devices. Unlike Resilio Sync, there's no folder limit and no “read-only” restriction on the free tier.
- 04
Configure versioning — go to “Advanced” per folder and pick your versioning strategy. The staggered option is a solid default: 24 hourly, 30 daily, and unlimited weekly snapshots.
- 05
Set up relay — Syncthing automatically connects devices over LAN or WAN via a global relay pool. If you're behind a strict firewall, it falls back to relay — all free, no subscription needed.
Frequently Asked Questions
Is Syncthing a good Resilio Sync alternative?
Yes — it's the closest open-source equivalent. Both use P2P syncing without a central cloud server, and Syncthing matches or exceeds Resilio Sync's free-tier capabilities. The key difference is that Syncthing is fully open source and free, with no paid tier or feature gating.
Is Syncthing free?
Yes, completely. Syncthing is MIT-licensed open source. No freemium, no pro features, no paid upgrades. What you get today is what the software will always be — free.
How does Syncthing compare to Resilio Sync in terms of speed?
In local networks (LAN), Syncthing often matches or beats Resilio Sync because it uses direct P2P connections without relaying. Over WAN with a relay fallback, speeds depend on relay server availability — but since the relay pool is free and globally distributed, most users report comparable performance to Resilio Sync's relay feature.
Does Syncthing support selective sync like Resilio Sync Pro?
Yes — but while Resilio Sync gated selective sync behind the Pro plan, Syncthing offers it for free. You can ignore specific files or patterns per folder (for example, *.tmp, *.bak, or entire subdirectories) using standard glob patterns.
Can I run Syncthing on a NAS without a GUI?
Yes — Syncthing has a headless mode and a command-line interface. Many users run Syncthing on Synology, QNAP, TrueNAS, or Unraid via Docker or native packages. The web UI is accessible from any browser on the same network.
How do I migrate from Resilio Sync to Syncthing?
Start by copying your synced folders to a new location (to avoid conflicts). Install Syncthing on your primary device, share the folder with your other devices using their device IDs, then point Syncthing to the original folder path. Once all devices are in sync, you can deactivate or uninstall Resilio Sync. A detailed migration guide is available in the Syncthing documentation.
How to switch without breaking your workflow
- 01
Make a backup copy of your currently synced folders before connecting a new device, so you have a clean rollback point if a path or versioning setting is wrong.
- 02
Install Syncthing on one primary device, then add your other devices using their device IDs and share one representative folder first.
- 03
Let the first sync finish, verify versioning and ignored-file rules, then retire Resilio Sync only after your normal workflow is stable.
Do not make the change a principle-only decision. A tool earns its place when it handles your normal work with less cost, less unwanted data exposure, or more control. Keep a rollback option until your daily workflow is genuinely stable.
Should you switch to Syncthing?
One of the purest open-source wins: your folders simply stay in sync across your devices. A successful migration starts with a small real project, not a feature checklist. Test the files, integrations, shortcuts, and collaboration steps you use every week before removing the existing tool.
Open source gives you inspectable code and a path away from vendor lock-in, but it does not eliminate tradeoffs. Support may be community-led, some commercial file formats may be imperfect, and self-hosted options require security updates and backups. Use the official website and source repository above to confirm current compatibility.