Cal.com vs siyuan
Is it time to switch? We break down the differences so you can stop bleeding money.
Choose Cal.com.
If you want to own your data, save money, and avoid vendor lock-in, Cal.com is more popular among developers.
What Actually Matters
No fluff — just the differences that affect your decision
Both open source, different licenses: Cal.com uses MIT, siyuan uses AGPL-3.0. Check the fine print if you're building commercial.
Both can run on your own metal with Docker. Full data ownership, no cloud dependency. We have deploy guides for each.
Cal.com (49.0k★) and siyuan (46.7k★) — both well-established. Neither is going anywhere.
Both written in TypeScript. Same ecosystem, same talent pool — makes switching easier if you ever need to.
Try both — most offer free tiers. The right pick depends on your stack size, team, and tolerance for DevOps.
Cal.com
The open-source Calendly alternative. Take control of your scheduling.
Why Choose Cal.com
- ✓Self-hosted scheduling — no data leaves your server
- ✓Deeply extensible with a plugin architecture and API
- ✓Round-robin, collective, and managed event types
Drawbacks
- ×Can be overkill for simple use cases
siyuan
Self-hosted personal knowledge management software built with TypeScript and Go, providing a private note-taking platform.
Why Choose siyuan
- ✓Built with TypeScript and Go — high-performance backend
- ✓Self-hosted solution — full control over data
- ✓AGPL-3.0 license — free to use and modify
Drawbacks
- ×Self-hosting can be complex
- ×Smaller ecosystem compared to proprietary alternatives
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