FHEM vs Mosquitto
A side-by-side comparison of two self-hosted home automation options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | FHEM | Mosquitto |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 62 · Good | 92 · Excellent |
| Category | Home Automation | Home Automation |
| License | GPL-2.0 | EPL-2.0 |
| Language | Perl | C |
| Setup difficulty | Hard | Easy |
| Min. RAM | 256 MB | 64 MB |
| Deployment | docker, bare-metal | docker, bare-metal |
| GitHub stars | ★ 22 | ★ 11,221 |
| First released | 2005 | 2009 |
| Replaces | SmartThings | SmartThings |
What are FHEM and Mosquitto?
FHEM
FHEM is a long-standing, GPL-licensed server for home automation used to control lights, heating, alarms, and many other devices. It supports a vast range of protocols through community modules.
- Vast protocol support
- Community module library
- Lightweight Perl server
- Long-term reliability
Mosquitto
Eclipse Mosquitto is a lightweight, open-source MQTT broker widely used as the messaging backbone for smart home setups. It targets users connecting IoT devices and automation tools. It is deployed via Docker or packages.
- Standards-compliant MQTT broker
- Tiny resource footprint
- TLS and authentication
- Bridges between brokers
FHEM vs Mosquitto: key differences
FHEM is written in Perl, while Mosquitto is built with C. Licensing differs — GPL-2.0 for FHEM versus EPL-2.0 for Mosquitto. Mosquitto is the lighter option, starting around 64 MB of RAM against 256 MB for FHEM. FHEM is the more established project (first released 2005), while Mosquitto arrived in 2009. Mosquitto has the considerably larger community, at 11,221 GitHub stars versus 22.
Why pick each one
Choose FHEM if…
- Extremely mature
- Runs on modest hardware
Watch out for
- Dated, technical interface
- Configuration is arcane
Choose Mosquitto if…
- Extremely lightweight
- Rock-solid reliability
- Ubiquitous in smart homes
Watch out for
- Just a broker, not automation
- Minimal management UI
Frequently asked questions
Is FHEM or Mosquitto better?
Mosquitto is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider FHEM if its specific feature set fits your needs better.
Are FHEM and Mosquitto free and open-source?
Yes. FHEM is licensed under GPL-2.0 and Mosquitto under EPL-2.0. Both can be self-hosted at no software cost.
Can I run FHEM and Mosquitto with Docker?
FHEM: yes. Mosquitto: yes.
Which is lighter on resources, FHEM or Mosquitto?
Mosquitto has the smaller minimum footprint at 64 MB of RAM, compared to about 256 MB for FHEM. Real-world usage depends on library size, user count, and enabled features.