Cal.com vs Cal.diy
| Tagline | Scheduling infrastructure for everyone, the open-source Calendly alternative | Open-source online appointment scheduling built on Cal.com |
| Category | Scheduling & Booking | Scheduling & Booking |
| Replaces | Calendly, Acuity Scheduling | Calendly, Acuity Scheduling |
| GitHub stars | 46k | 46k |
| Language | TypeScript | Nodejs |
| License | AGPL-3.0 | MIT |
| Self-host difficulty | 3/5 Moderate | 3/5 Moderate |
| Deploy options | One-Click Docker Docker Compose Manual | Docker Docker Compose Manual |
| Managed hosting | ||
| Last updated | 2 days ago | 2 days ago |
| View repo | View repo |
Where each falls short
The honest trade-offs — what you give up with each, versus the proprietary tools they replace.
Cal.com
- Some enterprise features (e.g. SAML SSO, advanced admin/insights, certain platform features) are gated behind a commercial/EE license even when self-hosting.
- Self-hosting requires PostgreSQL plus configuring numerous environment variables and OAuth credentials for calendar integrations.
- The core code is AGPL-3.0, which imposes copyleft obligations on modified network deployments.
- Upgrades between major versions occasionally require manual database migration work.
Cal.diy
- Self-hosted setup requires configuring PostgreSQL, email/SMTP, and OAuth providers
- Enterprise features (SAML SSO, workflows at scale, analytics) are cloud-only or require an enterprise license
- Payment collection integrations need additional third-party setup
- Admin UI for multi-tenant management is less polished than Calendly's hosted offering
Bottom line
Both are a similar lift to self-host. Open each guide below for deploy steps and the full feature gap.
Cal.com
Scheduling infrastructure for everyone, the open-source Calendly alternative