Claper 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?
FeatureClaperOpnForm
CategoryCalendar & ContactsCalendar & Contacts
LicenseGPL-3.0AGPL-3.0
LanguageElixirPHP
Setup difficultyMediumMedium
Min. RAM512 MB512 MB
Deploymentdockerdocker
GitHub stars★ 773★ 3,545
First released20262026
Replaces

Why pick each one

Choose Claper if…

  • Released under the GPL-3.0 license
  • First-class Docker support for quick deployment
  • Written in Elixir
  • Lightweight — runs in 512 MB RAM
Claper details

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
OpnForm details

Frequently asked questions

Is Claper 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 Claper and OpnForm free and open-source?

Yes. Claper is licensed under GPL-3.0 and OpnForm under AGPL-3.0. Both can be self-hosted at no software cost.

Can I run Claper and OpnForm with Docker?

Claper: yes. OpnForm: yes.

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