openHAB vs Domoticz: Which to Self-Host?
Quick Verdict
openHAB is the better choice if you want a full-featured, extensible home automation platform with strong protocol support and a modern UI. Domoticz wins if you need an ultra-lightweight system for minimal hardware or a simple setup with 433 MHz RF devices. For most people considering either of these over Home Assistant, openHAB is the more capable option.
Overview
openHAB is a Java-based (OSGi) open-source platform with 400+ bindings, a modern MainUI, and support for industrial protocols like KNX and Modbus. It’s maintained by the openHAB Foundation and has quarterly releases.
Domoticz is a C++-based lightweight home automation system. It runs on extremely constrained hardware, supports Z-Wave, Zigbee, MQTT, and 433 MHz RF natively, and uses Lua scripting (dzVents) for automations.
Both run locally with no cloud dependency. Neither matches Home Assistant’s integration count, but each serves a specific niche.
Feature Comparison
| Feature | openHAB | Domoticz |
|---|---|---|
| Integrations | 400+ bindings | ~200 hardware types |
| UI | MainUI (modern) + sitemaps | Web UI (functional, basic) |
| Mobile app | Basic apps (iOS/Android) | Third-party apps |
| Automation | DSL rules, Blockly, JavaScript | Lua/dzVents, Blockly |
| Language | Java (OSGi) | C++ |
| RAM (idle) | ~500 MB | ~50 MB |
| 433 MHz RF | Via RFXCOM binding | Native, excellent |
| KNX support | Native binding | Limited |
| Modbus support | Native binding | Plugin |
| MQTT | Native binding | Native |
| Z-Wave | Native binding | Native |
| Zigbee | Via Zigbee binding | Via Zigbee2MQTT |
| API | REST + SSE | JSON API |
| License | Eclipse Public License 2.0 | GPLv3 |
Installation Complexity
openHAB requires more initial configuration. The Docker setup involves multiple volume mounts and environment variables. Adding devices follows the Things → Channels → Items model, which is powerful but has a learning curve. The MainUI has improved significantly, but the concepts take time to internalize.
Domoticz is simpler to deploy and configure. Docker setup is minimal — one container, one volume. Adding devices is done through a straightforward Setup > Hardware menu. Lua scripting for automations is approachable if you have basic programming experience.
Domoticz is faster to get running. openHAB takes longer to set up but offers more structured configuration.
Performance and Resource Usage
| Resource | openHAB | Domoticz |
|---|---|---|
| RAM (idle) | ~500 MB | ~50 MB |
| RAM (loaded) | 600 MB - 1 GB | 100-200 MB |
| CPU (idle) | Low-Medium | Very low |
| Startup time | 60-120 seconds | 5-10 seconds |
| Docker image size | ~600 MB | ~200 MB |
| Minimum hardware | Raspberry Pi 4 (Pi 3 marginal) | Raspberry Pi Zero W |
Domoticz is 10x lighter on RAM. openHAB’s Java runtime is the reason — the JVM has a significant baseline memory footprint. On a Raspberry Pi 3 or Zero, Domoticz runs comfortably while openHAB struggles. On a Pi 4 or mini PC, both work fine.
Community and Support
openHAB has a solid community: ~13,000 GitHub stars, active forums, good documentation, and regular contributor activity. The openHAB Foundation provides organizational stability.
Domoticz has a smaller community: ~3,500 GitHub stars, a forum, and a wiki. The project is maintained by a small team. Development pace has slowed compared to earlier years, but it remains actively maintained.
Both communities are significantly smaller than Home Assistant’s, which is worth noting if community support matters to your decision.
Use Cases
Choose openHAB If…
- You need industrial protocol support (KNX, Modbus, EnOcean)
- You want structured configuration with the Things/Items model
- You prefer Java-based automation logic
- You want a modern UI with dashboard capabilities
- You’re building a medium-to-large smart home system
- You need strong vendor neutrality across many protocols
Choose Domoticz If…
- You run on very constrained hardware (Pi Zero, old NAS)
- You primarily use 433 MHz RF devices (RFXtrx, RFLink)
- You want the lightest possible home automation system
- You prefer Lua scripting for automations
- You have a small setup with straightforward requirements
- Fast startup and low resource usage are priorities
Final Verdict
openHAB is the better platform for most use cases where you’re choosing between these two. It has more bindings, a more modern UI, and better support for diverse protocols. The resource overhead is justified by the capabilities.
Domoticz makes sense for specific scenarios: Raspberry Pi Zero deployments, simple RF-based setups, or situations where every megabyte of RAM counts. It’s a solid, stable platform that does what it does well — it just does less.
If neither of these fully fits your needs, consider Home Assistant, which surpasses both in integrations, community, and UI quality.
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