head to head · open source
Cal.com vs Rallly
Cal.com has 48,529 GitHub stars, 15,154 forks, 1,432 open issues and last shipped 4 days ago. Rallly has 5,261 stars, 556 forks, 2 open issues and last shipped yesterday. Cal.com leads on adoption by 822% (48,529 vs 5,261 stars). Cal.com is written in TypeScript under MIT; Rallly is written in TypeScript under AGPL-3.0. Cal.com has attracted 31% as many forks as stars, Rallly 11%. Rallly was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 10 topic tags (next-auth, nextjs, postgresql, prisma), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
← all 8884 open source comparisons
Side by side
| Cal.com | Rallly | |
|---|---|---|
| GitHub stars | ★ 49K | ★ 5.3K |
| License | MIT | AGPL-3.0 |
| Written in | TypeScript | TypeScript |
| Last push | 2026-09-14 | 2026-09-17 |
| Forks | ⑂ 15K | ⑂ 556 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Cal.com if
- You weight community size — 49K stars and counting
- You want the MIT license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick Rallly if
- You want the Rallly feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches TypeScript
- You evaluated both and Rallly fits your workflow better
About Cal.com
Cal.diy is a fully open source, community maintained fork of Cal.com, stripped of all enterprise and commercial features. It provides a self hosted scheduling platform built on the T3 stack (Next.js, tRPC, Prisma, Tailwind CSS, Zod), licensed under MIT with no proprietary code or license keys required.
read the full Cal.com overview →
About Rallly
Rallly is an open source scheduling and collaboration tool built to help groups find the best date and time to meet. Instead of exchanging messages about availability, a person creates a poll with several candidate dates and times, shares the link, and participants vote on the options that work for them. It lives in the Business Software category, specifically Scheduling and Event Management, and positions itself as an open alternative to Calendly. The project is written in TypeScript and released under the AGPL 3.0 license, with the source hosted publicly and the hosted service available at rallly.co.…
read the full Rallly overview →
More in Business Software
Related comparisons
More Scheduling & Event Management projects
Compare either of these against the rest of the Scheduling & Event Management field.
Frequently asked questions
Is Cal.com or Rallly more popular?
Cal.com has 48,529 GitHub stars and Rallly has 5,261. Cal.com has the larger community by that measure.
Are Cal.com and Rallly free?
Both are open source. Cal.com is licensed under MIT and Rallly under AGPL-3.0. Neither carries a licence fee.
What is the difference between Cal.com and Rallly?
Cal.com is written in TypeScript and Rallly in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Cal.com or Rallly?
Choose Cal.com if you want the larger community (48,529 stars) or its MIT licence terms. Choose Rallly if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.