# Alternatives to Unison Unison is a free, open-source, cross-platform file synchronization tool that runs on Linux, macOS and Windows. Unlike rsync, it performs true two-way sync, detects conflicts when both replicas changed, and lets the user resolve them; it can sync over direct sockets or SSH tunnels. It remains actively maintained on GitHub, with releases as recent as May 2026. Unison ranks #6 of 11 in File sync, with an Alt Score of 81. It is licensed under GPL-3.0, free from Free and available on Windows, macOS and Linux. 12 of 12 checklist rows are verified against a public source. Source: https://altcatalog.com/alternatives/unison/ Category: File sync ## Where Unison stands out - **Open source** — 4 of 11 apps with a verified answer have this ## Overview - **Who it's for**: Unison is aimed at technical users, sysadmins, and developers who want to keep two file replicas (e.g. a laptop and a server, or two machines on different platforms) in sync from the command line or a simple GUI, without relying on a third-party cloud service. - **What you get**: Unison performs two-way, bidirectional synchronization between a pair of replicas: it detects updates on both sides, propagates non-conflicting changes automatically, and surfaces conflicting changes for manual resolution. It supports selective synchronization of specific paths, ignore patterns for excluded files, configurable file-versioning/backups, and a compression protocol similar to rsync for efficient transfer of changed data. - **How it works**: Unison runs as a command-line (or simple GUI) program on both replicas and connects them either via an ssh remote-shell tunnel or via a TCP/Unix-domain socket daemon (started with 'unison -socket'), requiring no kernel modifications or superuser privileges on either host. It maintains a private archive of prior synchronization state on each host to determine what changed since the last run, then updates each replica to reflect the other's non-conflicting changes. ## Profile - **License**: GPL-3.0 (verified 2026-07-30) - **Pricing model**: Free (verified 2026-07-30) - **Starts at**: Free (verified 2026-07-30) - **Platforms**: Windows, macOS, Linux - **Status**: active (verified 2026-07-30) ## Ranked alternatives | # | App | Alt Score | Licence | Platforms | |---|-----|-----------|---------|-----------| | 1 | [GoodSync](https://altcatalog.com/alternatives/goodsync.md) | 93 | Proprietary | Windows, macOS, Linux, iOS | | 2 | [Seafile](https://altcatalog.com/alternatives/seafile.md) | 93 | AGPL-3.0 | Windows, macOS, Linux, iOS | | 3 | [SyncBackPro](https://altcatalog.com/alternatives/syncbackpro.md) | 89 | Proprietary | Windows | | 4 | [Syncthing](https://altcatalog.com/alternatives/syncthing.md) | 89 | MPL-2.0 | Windows, macOS, Linux, Android | | 5 | [Syncovery](https://altcatalog.com/alternatives/syncovery.md) | 85 | Proprietary | Windows, macOS, Linux | | 6 | [ChronoSync](https://altcatalog.com/alternatives/chronosync.md) | 74 | ? | macOS | | 7 | [rclone](https://altcatalog.com/alternatives/rclone.md) | 74 | MIT | Windows, macOS, Linux, Android | | 8 | [FolderSync](https://altcatalog.com/alternatives/foldersync.md) | 62 | Proprietary | Windows, macOS, Linux, Android | | 9 | [FreeFileSync](https://altcatalog.com/alternatives/freefilesync.md) | 55 | Proprietary | Windows, macOS, Linux | | 10 | [Resilio Sync](https://altcatalog.com/alternatives/resilio-sync.md) | 40 | Proprietary | Windows, macOS, Linux, iOS | Alt Score = Verified coverage (90%) + Visibility (10%). See https://altcatalog.com/how-alt-score-works/ ## Feature comparison Legend: Yes / No / Partial / ? (not verified). | File sync checklist | Unison | GoodSync | Seafile | SyncBackPro | Syncthing | Syncovery | |---|---|---|---|---|---|---| | Pricing model | Free | Freemium | OSS + paid hosting | One-time | Free | One-time | | Starts at | Free | €29.95/yr | $8/user/month | ? | Free | $39.90 | | License | GPL-3.0 | Proprietary | AGPL-3.0 | Proprietary | MPL-2.0 | Proprietary | | Platforms | Windows, macOS, Linux | Windows, macOS, Linux, iOS, Android | Windows, macOS, Linux, iOS, Android, Web | Windows | Windows, macOS, Linux, Android | Windows, macOS, Linux | | Peer-to-peer (no server) | Yes | Yes | No | Yes | Yes | Yes | | Self-hostable server | Yes | Yes | Yes | Yes | No | Yes | | Selective sync | Yes | Yes | Yes | Yes | Yes | Yes | | Delta sync | Yes | Yes | Yes | Yes | Yes | Yes | | Conflict handling | Yes | Yes | Yes | Yes | Yes | Yes | | Untrusted-device encryption | No | Yes | Yes | Yes | Yes | Yes | | Bandwidth limits | Partial | Yes | Yes | Yes | Yes | Yes | | LAN sync | Yes | Yes | Yes | Yes | Yes | Yes | | File versioning | Yes | Yes | Yes | Yes | Yes | Yes | | Ignore patterns | Yes | Yes | Yes | Yes | Yes | Yes | | Mobile support | No | Yes | Yes | Partial | Partial | No | | Open source | Yes | No | Yes | No | Yes | No | ## Sources Sources for Unison. Each alternative is sourced on its own page. - **Pricing model**: Free — (verified 2026-07-30) - Note: No paid tier exists; project is free open-source software with no commercial offering. - Quote: “Unison is Free; full source code is available under the GNU Public License, Version 3.” - **Platforms**: Windows, macOS, Linux — (verified 2026-07-30) - Note: CI also builds for other Unix-like systems (FreeBSD, OpenBSD, NetBSD via pkgsrc) per the same page; only Windows/macOS/Linux map to the checklist vocabulary. - Quote: “Ubuntu is probably 20.04... macOS is built on macOS 10.15 with a target of 10.6... Windows is built with mingw, and will likely work on Windows 7 and up.” - **License**: GPL-3.0 — (verified 2026-07-30) - Quote: “GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007” - **Starts at**: Free — (verified 2026-07-30) - Quote: “Unison is Free; full source code is available under the GNU Public License, Version 3.” - **Status**: active — (verified 2026-07-30) - Note: Latest tagged release v2.54.0 published 2026-05-01; latest commit to master was 2026-07-23, one week before this research date. - Quote: “v2.54.0 ... 2026-05-01T00:33:56Z” - **Peer-to-peer (no server)**: Yes — (verified 2026-07-30) - Quote: “Unison works between any pair of machines connected to the internet, typically communicating over ssh, but also directly over TCP.” - **Self-hostable server**: Yes — (verified 2026-08-11) - **Selective sync**: Yes — (verified 2026-08-11) - **Delta sync**: Yes — (verified 2026-08-11) - **Conflict handling**: Yes — (verified 2026-08-11) - **Untrusted-device encryption**: No — (verified 2026-08-11) - **Bandwidth limits**: Partial — (verified 2026-07-30) - Note: This is the maxthreads concurrency preference, an indirect throttle, not a literal KB/s bandwidth cap. - Quote: “when Unison is used over a low-bandwidth link it may be helpful to set it lower (e.g. to 1) so that Unison doesn't soak up all the available bandwidth” - **LAN sync**: Yes — (verified 2026-08-11) - **File versioning**: Yes — (verified 2026-08-11) - **Ignore patterns**: Yes — (verified 2026-08-11) - **Mobile support**: No — (verified 2026-07-30) - Note: Enumerated CI platforms are Ubuntu, macOS, and Windows only; no iOS/Android binaries or apps are mentioned anywhere in the project's wiki or README. - Quote: “Note that there are no binaries for most operating systems, and no binaries for most CPU architectures. Binaries are limited to a small number of OS/CPU combinations, based on what github offers.” - **Open source**: Yes — (verified 2026-07-30) - Quote: “Unison is Free; full source code is available under the GNU Public License, Version 3.” --- Ranked by verified data, never by who paid. https://altcatalog.com/trust/