
Alf.io
Alf.io is an open source ticket reservation and event attendance management system for conferences, workshops, meetups, and trade shows.

Alf.io is an open source ticket reservation and event attendance management system for event organizers. It covers the full lifecycle from ticket sales and payments to check-in operations and reporting, with a strong focus on privacy and security.
Key Features
- Public ticket shop for ticket reservation and sales
- Backoffice/admin area for event setup and management
- Payment gateway integrations including Stripe, PayPal, Mollie, Revolut, and bank transfer options
- Reporting capabilities across the event lifecycle
- Extension mechanism to integrate with third-party tools (for example CRM systems)
- Mobile apps (iOS and Android) for attendee check-in and sponsor/exhibitor lead capture
- High-throughput, offline-capable check-in station support (including Raspberry Pi setups with encrypted attendee lists)
- Multi-language user interface
Use Cases
- Running ticketing and check-in for conferences, trade shows, workshops, and meetups
- On-site badge scanning and lead collection for sponsors/exhibitors
- Offline check-in and badge printing workflows for high-volume events
Limitations and Considerations
- Requires PostgreSQL (10+) and a Java 17 runtime for deployment
- Some payment methods require third-party accounts and configuration with their providers
Alf.io is suited for organizations that want control over event data and ticketing costs while still offering modern payment and check-in workflows. Its modular integrations and offline-capable check-in options make it practical for both small meetups and larger events.