# Unison file synchronizer

24 Hacker News commenters recommended Unison file synchronizer and 3 criticized it, November 2025 to November 2026. It was recommended in 11 of 13 months. It meets the Hacker Approved badge rule.

**Verdict:** Free two-way file synchronizer that keeps files in sync across computers and asks for help on conflicts. Critics warn two-way sync can wipe files and there are no mobile apps.

## Why people recommend it

- Keeps files in sync, works well (5 comments): "Git-annex, Unison, and Syncthing are much better at keeping files synchronized across devices." ([source](https://news.ycombinator.com/item?id=46173050)) "sometimes "unison" works better, or sometimes "syncthing"" ([source](https://news.ycombinator.com/item?id=49835041)) "rsync and unison works great" ([source](https://news.ycombinator.com/item?id=48299334))
- Two-way sync asks for help (2 comments): "that's two-way sync, and it always prompted to ask for help by design" ([source](https://news.ycombinator.com/item?id=47769064)) "it always prompted to ask for help by design" ([source](https://news.ycombinator.com/item?id=47766686))

## What people warn about

- No mobile apps (2 comments): "it is a blast from the past written in ocaml and there is no Android app" ([source](https://news.ycombinator.com/item?id=45800157)) "Unfortunately it has no mobile apps, though." ([source](https://news.ycombinator.com/item?id=45800178))
- Hard to understand for newcomers (2 comments): "Unison: Language server failed to connect, is there a UCM running?" ([source](https://news.ycombinator.com/item?id=46053163)) "which is a head of the time but... not so many people understand it" ([source](https://news.ycombinator.com/item?id=49979669))

## Alternatives hackers recommend

- [SyncTrain](https://hackerapproved.com/p/synctrain.md): 9 recommend
- [FolderSync](https://hackerapproved.com/p/foldersync.md): 6 recommend
- [Resilio Sync](https://hackerapproved.com/p/resilio-sync.md): 5 recommend

## Cite as

Hacker Approved, "Unison file synchronizer", https://hackerapproved.com/p/unison/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).