OpenCloud 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.
OpenCloud
Modern open-source file platform from ownCloud team
VS
Unison
Bidirectional file synchronizer with conflict detection
| Feature | OpenCloud | Unison |
|---|---|---|
| Deploy effort | Under-an-hour setup | Read-the-docs project |
| Health score | 90 · Excellent | 88 · Excellent |
| Category | File Sync & Storage | File Sync & Storage |
| License | Apache-2.0 | GPL-3.0 |
| Language | Go | OCaml |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 64 MB |
| Deployment | docker | bare-metal, binary |
| GitHub stars | ★ 6,056 | ★ 5,493 |
| First released | 2025 | 1999 |
| Replaces | Dropbox, Google Drive | Dropbox |
What are OpenCloud and Unison?
OpenCloud
OpenCloud is a modern open-source file sync, share, and collaboration platform built on a microservice architecture. It targets organizations wanting a current, lightweight content collaboration server. It is deployed via Docker Compose.
- Microservice-based architecture
- Web-based collaboration
- Lightweight Go backend
- Compatible desktop clients
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
OpenCloud vs Unison: key differences
OpenCloud is written in Go, while Unison is built with OCaml. Licensing differs — Apache-2.0 for OpenCloud versus GPL-3.0 for Unison. Unison is the lighter option, starting around 64 MB of RAM against 512 MB for OpenCloud. Unison is the more established project (first released 1999), while OpenCloud arrived in 2025. OpenCloud lists first-class Docker deployment; Unison does not.
Why pick each one
Choose OpenCloud if…
- Modern, fast codebase
- Lightweight footprint
- Permissively licensed
Watch out for
- Very new project
- Smaller ecosystem so far
Choose Unison if…
- Very reliable
- Fine-grained control
Watch out for
- Dated GTK interface
- Version matching between hosts
Frequently asked questions
Is OpenCloud or Unison better?
Neither is universally better. OpenCloud has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are OpenCloud and Unison free and open-source?
Yes. OpenCloud is licensed under Apache-2.0 and Unison under GPL-3.0. Both can be self-hosted at no software cost.
Can I run OpenCloud and Unison with Docker?
OpenCloud: yes. Unison: check the project docs for container support.
Which is lighter on resources, OpenCloud or Unison?
Unison has the smaller minimum footprint at 64 MB of RAM, compared to about 512 MB for OpenCloud. Real-world usage depends on library size, user count, and enabled features.