Open-source Resilio Sync alternatives

Syncthing is a continuous file synchronization program that keeps files in sync between two or more computers. It is written in Go and released under the MPL-2.0 license, and its peer-to-peer design means your devices exchange files with each other directly rather than through a central storage service.

The project ranks its goals in order of importance: protect users from data loss, stay secure against eavesdropping and tampering, be easy to use, work automatically with minimal interaction, run on every common computer, and focus on empowering individuals. Several graphical front ends exist for Windows, Mac and Linux, and the repository includes sample files for running it as a background service.

Syncthing can also be run in Docker, and a getting-started guide covers setup. It suits individuals and small groups who want to sync folders between laptops, desktops and servers they control instead of relying on a hosted file-sharing service, and who value open, auditable software.

Unison is a file-synchronization tool for POSIX systems such as BSD, GNU/Linux and macOS, as well as Windows. It keeps two copies of a directory tree in step. The copies can sit on different machines or on separate disks of one machine, can each be modified on their own, and are reconciled later by carrying every side's changes across to the other.

It differs from plain mirroring or backup tools in handling edits made on both sides: changes that do not conflict are propagated automatically, while conflicting ones are detected and displayed. It runs as an ordinary user-level program, so no kernel changes, superuser rights or FUSE are needed, and data is copied so it can be read and written offline.

Machines are usually connected over ssh, though direct TCP also works, and the tool is careful with bandwidth so it performs reasonably over slow links. It can synchronize a Windows laptop with a Unix server, for example. Written in OCaml and licensed under GPL-3.0, it has been in use for more than twenty-five years.

The syncthing-macos project is the official native macOS application bundle for Syncthing, an open-source, peer-to-peer tool for keeping folders synchronized across your own devices without a central cloud server. The bundle packages its own Syncthing instance and wraps the background process, so it feels like a normal Mac app rather than a command-line utility managed through a browser.

A tray menu lets you open the Syncthing web interface in your preferred browser and manage the app from the menu bar. The README notes that Syncthing version 2 is the supported version since 23 February 2026 and requires at least macOS 12, while version 1 is deprecated and will not receive updates. The wrapper is written in Objective-C and Swift and described as frugal and simple.

The macOS wrapper is MIT-licensed, and the bundled Syncthing is open source as well. It runs entirely on your own Mac, with no vendor-hosted sync service, which suits people who want private file synchronization or backup between computers and phones.

Syncthing-Fork is an Android app that wraps Syncthing, the peer-to-peer file synchronization tool, so it can be used conveniently on a phone or tablet. The project was forked from the official syncthing-android repository, which is described as deprecated, and the former maintainers are acknowledged in the README. It is written in Java.

Builds are published in the releases section of the repository and on F-Droid. The project asks users to seek help on the forum and social media before opening tracker issues, and it publishes a wiki knowledge base, building and development notes and a privacy policy. A wiki article explains how to switch from the deprecated official app.

The README also lists community projects that extend or depend on the app. They include DecSync-based apps for syncing contacts, calendars, tasks and RSS without a server, and a tool that pauses Syncthing-Fork while the device sleeps. The project is licensed under MPL-2.0 and had its latest release listed as v2.1.5.0.