ClearFlask vs khal
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
khal
Command-line calendar built on CalDAV
| Feature | ClearFlask | khal |
|---|---|---|
| Category | Calendar & Contacts | Calendar & Contacts |
| License | AGPL-3.0 | MIT |
| Language | Java | Python |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 64 MB |
| Deployment | docker | binary, source |
| GitHub stars | ★ 446 | ★ 3,039 |
| First released | 2025 | 2013 |
| Replaces | — | Google Calendar |
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 khal if…
- Released under the MIT license
- Active community (3k GitHub stars)
- Written in Python
- Tiny footprint — runs in 64 MB RAM
Frequently asked questions
Is ClearFlask or khal better?
Neither is universally better. khal has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are ClearFlask and khal free and open-source?
Yes. ClearFlask is licensed under AGPL-3.0 and khal under MIT. Both can be self-hosted at no software cost.
Can I run ClearFlask and khal with Docker?
ClearFlask: yes. khal: check the project docs for container support.