Upspin vs Unison
A side-by-side comparison of two self-hosted file sync & storage options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Upspin | Unison |
|---|---|---|
| Deploy effort | Read-the-docs project | Read-the-docs project |
| Health score | 37 · At risk | 88 · Excellent |
| Category | File Sync & Storage | File Sync & Storage |
| License | BSD-3-Clause | GPL-3.0 |
| Language | Go | OCaml |
| Setup difficulty | Hard | Medium |
| Min. RAM | 128 MB | 64 MB |
| Deployment | binary, source | bare-metal, binary |
| GitHub stars | ★ 6,404 | ★ 5,528 |
| First released | 2016 | 1999 |
| Replaces | Dropbox | Dropbox |
What are Upspin and Unison?
Upspin
Upspin is an experimental framework from Google for naming and sharing files securely across the internet. It gives every file a globally unique name and end-to-end encrypted access control.
- Global file naming system
- End-to-end encrypted sharing
- Fine-grained access groups
Unison
Unison is a mature bidirectional file synchronization tool that reconciles changes made independently on two replicas. It detects conflicts, preserves both versions, and works over SSH for secure remote syncing.
- True bidirectional sync
- Conflict detection
- Works over SSH
- Cross-platform replicas
Upspin vs Unison: key differences
Upspin is written in Go, while Unison is built with OCaml. Licensing differs — BSD-3-Clause for Upspin versus GPL-3.0 for Unison. Unison is the lighter option, starting around 64 MB of RAM against 128 MB for Upspin. Unison is the more established project (first released 1999), while Upspin arrived in 2016.
Why pick each one
Choose Upspin if…
- Released under the BSD-3-Clause license
- Mature project with 6.4k GitHub stars
- Written in Go
- Tiny footprint — runs in 128 MB RAM
Choose Unison if…
- Very reliable
- Fine-grained control
Watch out for
- Dated GTK interface
- Version matching between hosts
Frequently asked questions
Is Upspin or Unison better?
Neither is universally better. Upspin has the larger community, while Unison is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are Upspin and Unison free and open-source?
Yes. Upspin is licensed under BSD-3-Clause and Unison under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Upspin and Unison with Docker?
Upspin: check the project docs for container support. Unison: check the project docs for container support.
Which is lighter on resources, Upspin or Unison?
Unison has the smaller minimum footprint at 64 MB of RAM, compared to about 128 MB for Upspin. Real-world usage depends on library size, user count, and enabled features.