Cal.diy vs vdirsyncer
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?
Cal.diy
Online appointment scheduling system
VS
vdirsyncer
Synchronize calendars and contacts via CalDAV/CardDAV
| Feature | Cal.diy | vdirsyncer |
|---|---|---|
| Category | Calendar & Contacts | Calendar & Contacts |
| License | MIT | BSD-3-Clause |
| Language | TypeScript | Python |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 64 MB |
| Deployment | bare-metal | binary, source |
| GitHub stars | ★ 47,334 | ★ 1,859 |
| First released | 2026 | 2014 |
| Replaces | — | iCloud sync |
Why pick each one
Choose Cal.diy if…
- Released under the MIT license
- Mature project with 47.3k GitHub stars
- Written in TypeScript
- Lightweight — runs in 512 MB RAM
Choose vdirsyncer if…
- Released under the BSD-3-Clause license
- Active community (1.9k GitHub stars)
- Written in Python
- Tiny footprint — runs in 64 MB RAM
Frequently asked questions
Is Cal.diy or vdirsyncer better?
Neither is universally better. Cal.diy has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Cal.diy and vdirsyncer free and open-source?
Yes. Cal.diy is licensed under MIT and vdirsyncer under BSD-3-Clause. Both can be self-hosted at no software cost.
Can I run Cal.diy and vdirsyncer with Docker?
Cal.diy: check the project docs for container support. vdirsyncer: check the project docs for container support.