Rallly vs Cal.com: Open Source Scheduling Tools in 2026

The Scheduling Tool Problem

Calendly charges $10-20/user/month. Doodle charges for features that should be free. Both send your meeting data through their servers.

The open source scheduling landscape has split into two clear use cases:

1. Group availability polling (like Doodle): "When can everyone meet?" — This is Rallly
2. Individual booking pages (like Calendly): "Book time on my calendar" — This is Cal.com

Understanding which use case you need makes the choice straightforward.

TL;DR

• Rallly (5K+ stars): Best for group scheduling polls. Share a link, everyone marks availability, find the best time. Open source Doodle alternative. No accounts required for participants.
• Cal.com (35K+ stars): Best for individual booking pages. Share your booking link, others book time based on your calendar availability. Complete open source Calendly alternative.

Quick Comparison

Feature	Rallly	Cal.com
GitHub Stars	5K+	35K+
Primary use case	Group availability polls	Individual booking links
Calendar sync	Limited	Full (Google, Outlook, iCal)
No account needed for guests	Yes	Yes
Team scheduling	Yes (via polls)	Yes (round-robin, etc.)
Payments	No	Yes
Video conferencing	No	Yes (Zoom, Meet, etc.)
Workflows/automations	No	Yes
Self-hosting	Easy	Medium
License	AGPL-3.0	AGPL-3.0

Rallly — Best Group Availability Polling

Rallly is a focused tool for one thing: figuring out when a group of people can meet. Create a poll with time options, share a link, participants mark their availability — no accounts required.

What Makes It Stand Out

Zero friction for participants: Share a poll link, others click their available times. No Rallly account needed for responders. This is the single biggest advantage over many alternatives.

Clean interface: The scheduling grid is intuitive — rows for people, columns for time slots, marks for availability. At a glance, you see when everyone is free.

Comments: Add discussion to the poll — context, notes, or final confirmation of the chosen time.

Email notifications: Notify all participants when you finalize a time.

Final date: Mark the selected time as final, automatically notify all participants.

Use Cases

• Team meeting scheduling across multiple people
• Recurring meeting time selection ("When should we schedule our weekly standup?")
• Event planning with external participants who don't have accounts
• Conference scheduling, workshop slots

Self-Hosting

git clone https://github.com/lukevella/rallly-selfhosted
cd rallly-selfhosted
cp .env.example .env
# Configure email settings
docker compose up -d

Rallly runs as a single Docker container with PostgreSQL. Very simple deployment — one of the easiest self-hosting setups in this article series.

Email configuration: Rallly needs an SMTP provider to send invitation and notification emails. Configure with any SMTP service (Gmail, Resend, AWS SES).

Limitations

• Not a Calendly replacement: Rallly doesn't sync with your calendar or provide a "book a time on my calendar" link. It's group polling, not booking.
• No individual scheduling pages
• No calendar integrations
• No payment processing

Best for: Teams scheduling internal meetings, event organizers coordinating group availability, anyone who needs a free Doodle alternative.

Cal.com — Complete Calendly Replacement

Cal.com (35K+ stars) is the most comprehensive open source scheduling platform. It provides everything Calendly offers — booking pages, calendar sync, team scheduling, workflows, and payments — in a self-hostable package.

What Makes It Stand Out

Calendar sync: Two-way sync with Google Calendar, Outlook, iCloud, and CalDAV. Blocks time when you're busy based on your actual calendar.

Event types: Create different booking types:

• 15-min consultation
• 60-min project kickoff
• Recurring office hours
• Custom durations

Team scheduling:

• Round-robin: Distribute bookings among team members based on availability
• Collective: Require all team members to be available
• Individual: Book with a specific person

Availability settings: Set working hours, date ranges, buffer time between meetings, minimum notice period.

Integrations: Zoom, Google Meet, Microsoft Teams, Webex — auto-generate video conference links for bookings.

Payments: Integrate with Stripe to charge for consultations or sessions.

Workflows: Automated emails before/after meetings, SMS reminders, webhook triggers.

Embed: Embed your booking widget on any website.

Self-Hosting

Cal.com has a more complex self-hosting setup than Rallly:

git clone https://github.com/calcom/cal.com
cd cal.com
cp .env.example .env
# Configure:
# - DATABASE_URL (PostgreSQL)
# - NEXTAUTH_SECRET
# - CALENDSO_ENCRYPTION_KEY
# - Email SMTP
# - Calendar OAuth credentials (optional)
yarn install
yarn db:deploy
yarn build
yarn start

Or using Docker:

docker compose -f docker-compose.yml up -d

Cal.com requires PostgreSQL, Redis, and the main application. More setup than Rallly but well-documented.

Cal.com Cloud: The managed cloud service (cal.com) has a free tier for individuals and paid plans for teams ($12/user/month). Self-host if you need unlimited users or data residency.

Limitations

• More complex to self-host than Rallly
• Requires OAuth setup for calendar integrations (Google OAuth app configuration)
• No group availability polling like Rallly

Best for: Freelancers, consultants, sales teams, and any individual or organization that needs an appointment booking system.

Using Both Together

Many teams use both tools for different scenarios:

Use Rallly for: Initial team meeting time selection, conference scheduling, group coordination

Use Cal.com for: Client booking links, intake consultations, recurring office hours, any "book with me" use case

Cost Comparison

Commercial Tools Annual Costs

Tool	Plan	Per User/Month	Annual (5 users)
Calendly	Essentials	$8	$480
Calendly	Professional	$12	$720
Doodle	Business	$14.95	$897

Self-Hosted

Tool	Server	Annual
Rallly (Hetzner CAX11)	$4/mo	$48
Cal.com (Hetzner CPX21)	$6.50/mo	$78
Both on same server	$10/mo	$120

You can run both Rallly and Cal.com on a single $10/month VPS, replacing $480-897/year in commercial tool subscriptions.

Migration from Doodle to Rallly

Rallly's core use case (time polls) maps directly to Doodle:

1. Create a new poll in Rallly
2. Add the same time options you'd add in Doodle
3. Copy and share the poll link
4. Participants interact the same way — no accounts needed

The migration is behavioral (team members learn to use a new link), not technical.

Migration from Calendly to Cal.com

Calendly and Cal.com have similar workflows:

1. Set up Cal.com (self-hosted or cloud)
2. Connect your calendar (Google/Outlook)
3. Configure your availability
4. Create event types matching your Calendly types
5. Update your booking link on your website and email signature
6. Cancel Calendly subscription

Historical booking data doesn't transfer, but since scheduling is forward-looking (you care about future bookings, not past ones), this is rarely a concern.

Find Your Scheduling Tool

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