Cal.com vs Rallly: Which Scheduling Tool to Self-Host?
Quick Verdict
Cal.com and Rallly solve different scheduling problems. Cal.com is a Calendly replacement — public booking pages where people pick a time slot from your calendar availability. Rallly is a Doodle replacement — group polls where multiple people vote on their preferred dates. If you need appointment booking, use Cal.com. If you need group scheduling polls, use Rallly.
Overview
Cal.com is an open-source scheduling platform built with Next.js. It provides public booking pages, calendar integration (Google Calendar, Outlook, CalDAV), round-robin team scheduling, payment collection via Stripe, and webhook automations. It’s a full Calendly replacement designed for professional booking workflows. Requires PostgreSQL and ~2 GB RAM.
Rallly is an open-source scheduling poll tool, also built with Next.js. It creates polls where you propose date/time options and participants vote on their availability — like Doodle. Participants don’t need accounts. Lightweight at ~200 MB RAM, with PostgreSQL as its only dependency beyond SMTP for email notifications.
Feature Comparison
| Feature | Cal.com | Rallly |
|---|---|---|
| Primary use case | Appointment booking (1-on-1 or group) | Group availability polling |
| Replaces | Calendly, Acuity, SavvyCal | Doodle, When2Meet |
| Booking pages | Yes (public, shareable) | No |
| Group polls | Limited (collective scheduling) | Yes (core feature) |
| Calendar integration | Google, Outlook, CalDAV, Apple | None |
| Participant accounts required | Depends on configuration | No — vote via link |
| Team scheduling | Yes (round-robin, collective) | No |
| Payment collection | Yes (Stripe integration) | No |
| Webhooks & automation | Yes | No |
| Recurring events | Yes | No |
| Email notifications | Yes | Yes (SMTP required) |
| Custom branding | Yes | Limited |
| API | REST + Webhooks | No public API |
| Mobile-friendly | Yes | Yes |
| SSO/SAML | Enterprise tier | No |
| Database | PostgreSQL | PostgreSQL |
| License | AGPLv3 (with enterprise tier) | AGPLv3 |
Installation Complexity
| Aspect | Cal.com | Rallly |
|---|---|---|
| Containers | 2+ (app + PostgreSQL) | 2 (app + PostgreSQL) |
| RAM requirement | ~2 GB minimum | ~512 MB minimum |
| Environment variables | 15+ (database, SMTP, calendar OAuth keys) | 8–10 (database, SMTP, secret) |
| Domain required | Yes (for OAuth calendar integrations) | No (helpful for sharing poll links) |
| SMTP required | Yes | Yes |
| Time to first use | ~15–20 minutes | ~5 minutes |
| Calendar OAuth setup | Yes (Google/Outlook developer apps) | Not applicable |
Cal.com’s complexity comes from calendar integrations — you need OAuth credentials from Google and/or Microsoft to sync calendars. Without them, Cal.com still works but loses its primary advantage over a static booking form. Rallly needs only SMTP credentials and a secret key.
Performance and Resource Usage
| Metric | Cal.com | Rallly |
|---|---|---|
| RAM (idle) | ~300–400 MB | ~150–200 MB |
| RAM (under load) | ~500–800 MB | ~300–500 MB |
| CPU | Low–Medium | Low |
| Disk | 10–20 GB | 500 MB + database |
| PostgreSQL overhead | ~200 MB | ~100–200 MB |
Both are Next.js applications, but Cal.com is significantly larger — it includes calendar sync workers, webhook processing, and payment handling. Rallly is minimal by comparison.
Community and Support
| Metric | Cal.com | Rallly |
|---|---|---|
| GitHub stars | ~34,000 | ~3,600 |
| License | AGPLv3 + enterprise | AGPLv3 |
| Update frequency | Very frequent (weekly) | Regular (monthly) |
| Documentation | Comprehensive | Good |
| Paid tier | Yes (Cal.com hosted + enterprise) | Yes (hosted tier) |
Cal.com has a massive community and corporate backing. Rallly is a smaller project maintained by a single developer but well-built and stable.
Use Cases
Choose Cal.com If…
- You need public booking pages (clients book time with you)
- Calendar integration is essential (Google Calendar, Outlook sync)
- You want round-robin or collective team scheduling
- You need payment collection for consultations
- You’re replacing Calendly, Acuity, or SavvyCal
Choose Rallly If…
- You need group scheduling polls (finding a time that works for everyone)
- Participants shouldn’t need accounts or calendar access
- You want the simplest possible setup
- You’re on limited hardware (512 MB RAM is enough)
- You’re replacing Doodle or When2Meet
- You just want to share a link and let people vote on dates
Final Verdict
These tools complement each other more than they compete. Cal.com is for structured appointment booking — think “clients booking 30-minute consultations.” Rallly is for group coordination — think “when should our team have dinner next Friday?”
If you must pick one: Cal.com is the more versatile tool. It can handle basic group scheduling through its collective event types, even if it’s not as elegant as Rallly’s polling interface. Rallly cannot replicate Cal.com’s booking pages, calendar sync, or payment features.
For many self-hosters, running both makes sense — Cal.com for professional scheduling and Rallly for casual group polls. Together they use ~700 MB of RAM and replace two categories of paid SaaS.
Related
Get self-hosting tips in your inbox
Get the Docker Compose configs, hardware picks, and setup shortcuts we don't put in articles. Weekly. No spam.
Comments