ClearFlask vs OpnForm
A side-by-side comparison of two self-hosted calendar & contacts options — licensing, setup difficulty, resource needs, and what each one replaces.
Not the right match-up?
ClearFlask
Community-feedback tool for managing incoming feedback and
VS
OpnForm
Beautiful open-source form builder
| Feature | ClearFlask | OpnForm |
|---|---|---|
| Category | Calendar & Contacts | Calendar & Contacts |
| License | AGPL-3.0 | AGPL-3.0 |
| Language | Java | PHP |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 512 MB |
| Deployment | docker | docker |
| GitHub stars | ★ 446 | ★ 3,545 |
| First released | 2025 | 2026 |
| Replaces | — | — |
Why pick each one
Choose ClearFlask if…
- Released under the AGPL-3.0 license
- First-class Docker support for quick deployment
- Written in Java
- Lightweight — runs in 512 MB RAM
Choose OpnForm if…
- Released under the AGPL-3.0 license
- First-class Docker support for quick deployment
- Active community (3.5k GitHub stars)
- Written in PHP
Frequently asked questions
Is ClearFlask or OpnForm better?
Neither is universally better. OpnForm has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are ClearFlask and OpnForm free and open-source?
Yes. ClearFlask is licensed under AGPL-3.0 and OpnForm under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run ClearFlask and OpnForm with Docker?
ClearFlask: yes. OpnForm: yes.