Comparison
VoxelBooking
vs Cal.com.
Both can be self-hosted. Different architectures.
Different booking patterns.
VoxelBooking
Four booking patterns: time slots, resources, capacity, events. Multi-business architecture. PHP/MySQL. Full source code. No Docker, no Redis, no Node.js required. Runs on standard shared hosting.
Cal.com
Appointment and meeting scheduling with calendar sync. Open source (AGPL). Node.js/TypeScript/PostgreSQL. Also available as managed SaaS.
Model
Two open-source booking systems.
VoxelBooking
PHP/MySQL booking software with four booking patterns, multi-business architecture, and branded pages per tenant.
AGPL-3.0 licensed. Built for standard hosting.
Cal.com
Node.js booking infrastructure for appointments, calendar sync, team scheduling, routing, and managed hosting.
AGPL licensed community source. Managed plans available.
Features
Feature by feature.
| Feature | VoxelBooking | Cal.com |
|---|---|---|
| Booking patterns | Time slots, resources, capacity, events | Meeting and appointment scheduling |
| Multi-business | VoxelBooking supports multiple client businesses | Team and organization accounts |
| Tech stack | PHP 8.3+, MySQL 8.0+ | Node.js, TypeScript, PostgreSQL |
| Hosting requirements | Shared hosting or VPS | VPS with Docker (recommended) |
| Calendar sync | Not available in v1 | Google, Outlook, Apple Calendar |
| Software model | Open source, self-hosted | Open source community and managed SaaS |
| License | AGPL-3.0 license | AGPL license |
| Source code | Full source included | Open source on GitHub |
| Branded booking pages | ✓ Custom colors, logo, cover image | Customizable booking pages |
| Restaurant reservations | Capacity pattern with party sizes | Not a reservation system |
| Hotel or room booking | Resource pattern with date ranges | Not a room booking system |
| Event registration | Events with participant limits | Group event types |
| Embed widget | One-line JavaScript embed | Embed and React component |
| API | REST API included | Full REST and webhook API |
| Round-robin scheduling | Not available in v1 | ✓ Built-in |
| Payment collection | Not available in v1 | Stripe integration |
Their strengths
Where Cal.com wins.
Native calendar sync
Two-way sync with Google Calendar, Outlook, and Apple Calendar. Cal.com reads your availability in real time. VoxelBooking manages availability through its own schedule system.
Open-source community
Cal.com has a large AGPL-licensed community and a public contribution path. Developers can inspect the code, fork it, and contribute upstream. VoxelBooking ships as a smaller open-source project with a focused PHP/MySQL stack.
Round-robin and collective scheduling
Assign meetings across team members automatically. Cal.com handles availability conflicts across multiple calendars. VoxelBooking focuses on staff-based availability within its own system.
Our strengths
Where VoxelBooking wins.
Four booking patterns, not one
Cal.com handles appointment scheduling. VoxelBooking also covers room bookings (date ranges, per-night pricing), restaurant reservations (party sizes, remaining capacity), and event registration (participant limits, waitlists). One system for salons, hotels, restaurants, and yoga studios.
Multi-business architecture
VoxelBooking supports multiple client businesses from one installation. Create a tenant for each client with isolated data, branded booking pages, and separate staff. Designed for freelancers and agencies managing multiple local businesses.
Standard PHP hosting
PHP 8.3+ and MySQL 8.0+. No Docker, no Redis, no Node.js at runtime. Upload the files, run the installer, open the dashboard. Works on shared hosting, any VPS, or dedicated servers.
AGPL-3.0 license
VoxelBooking uses the AGPL-3.0 license and keeps the full source code available from the project repository. The license model matches self-hosted deployment, modification, and commercial use.
Summary
The verdict.
Choose Cal.com if you need calendar sync with Google and Outlook, round-robin team scheduling, and an open-source codebase you can contribute to. Cal.com is the strongest self-hosted option for 1:1 meeting scheduling.
Choose VoxelBooking if you need more than appointment scheduling: room bookings, restaurant reservations, event registration, and multiple businesses from one installation on standard PHP hosting.
Wondering about the broader SaaS vs self-hosted question? Read our comparison of the two models.
Get started
Own your booking system.
Full source code. Four booking patterns. Standard PHP hosting.