Cal.com
Scheduling infrastructure for everyone, the open-source Calendly alternative
Overview
Cal.com (formerly Calendso) is the leading open-source scheduling platform. It supports event types, team scheduling, round-robin, collective availability, calendar sync (Google, Outlook, CalDAV), payments via Stripe, and an extensive app/integration ecosystem. It can be self-hosted or used via its managed cloud, and offers a full API and white-labeling.
Key features
- Configurable event types with collective, round-robin, and team scheduling
- Calendar sync with Google, Outlook, and CalDAV
- Stripe payments for paid bookings
- Full API and white-labeling support
- App and integration ecosystem
- Self-host via One-Click, Docker, Docker Compose, or manual; managed cloud available
Our take
Cal.com is the most full-featured open-source scheduling tool around, and it shows: team and round-robin scheduling, calendar sync across the major providers, Stripe payments, white-labeling, and a real API make it a credible Calendly replacement rather than a toy. That breadth is also the trade-off for self-hosters. It's a large application with a fair number of moving parts and integrations to configure, so a manual deploy is more involved than the difficulty rating suggests once you start wiring up calendars, OAuth, and payments. The AGPL license means you'll want to read the terms if you're embedding it in a commercial product. If you don't want the operational overhead, the managed cloud carries the same feature set.
Ideal for: Teams and developers who need a customizable, API-driven Calendly replacement they can brand and extend.
Where it falls short of Calendly
- 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.
We list the gaps honestly so you can decide if the trade-off is worth owning your data.
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