Business · Updated October 2026
Calendly is a scheduling tool that lets people book time on your calendar. If you would rather own your tools, here are 4 open source alternatives to Calendly, ranked by GitHub stars. Each one is free to use under its license, and you can read, change, and often self-host the code.
The most popular is cal.diy with 49.2k stars, and the most recently updated is Rallly, with a commit on Oct 21, 2026.
| Project | Stars | License | Language | Last commit |
|---|---|---|---|---|
 cal.diy | 49.2k | MIT | TypeScript | Oct 19, 2026 |
 Rallly | 5.3k | AGPL-3.0 | TypeScript | Oct 21, 2026 |
 Easy!Appointments | 4.5k | GPL-3.0 | PHP | Oct 19, 2026 |
 Hi.Events | 4.1k | Other | PHP | Oct 21, 2026 |
by calcom
Scheduling infrastructure for absolutely everyone.
by lukevella
Rallly is an open-source scheduling and collaboration tool designed to make organizing events and meetings easier.
by alextselegidis
:date: Easy!Appointments - Self Hosted Appointment Scheduler
by HiEventsDev
Open-source event management and ticket selling platform — perfect for concerts, conferences, and everything in between 🎟️ If you find this project helpful, please consider giving us a star ⭐️
By GitHub stars, cal.diy is the most popular open source alternative to Calendly right now, with 49.2k stars, followed by Rallly and Easy!Appointments. The best fit depends on your setup, so compare their licenses, languages, and recent activity in the table above.
Yes. All 4 projects on this page are open source, so the software itself is free to use, study, and change. Some of them also sell a hosted version or paid support.
Rallly (last commit Oct 21, 2026), Hi.Events (last commit Oct 21, 2026), and cal.diy (last commit Oct 19, 2026) have the most recent commits. Licenses on this list include MIT, AGPL-3.0, and GPL-3.0.
