Gajim vs MongooseIM
A side-by-side comparison of two self-hosted matrix & xmpp options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Gajim | MongooseIM |
|---|---|---|
| Deploy effort | Read-the-docs project | Under-an-hour setup |
| Category | Matrix & XMPP | Matrix & XMPP |
| License | GPL-3.0 | GPL-2.0 |
| Language | Python | Erlang |
| Setup difficulty | Easy | Hard |
| Min. RAM | 128 MB | 1,024 MB |
| Deployment | binary, source | docker, bare-metal, source |
| GitHub stars | ★ 600 | ★ 1,760 |
| First released | 2005 | 2012 |
| Replaces | Skype, Slack | Slack, WhatsApp |
What are Gajim and MongooseIM?
Gajim
Gajim is a cross-platform XMPP instant messaging client written in Python with a GTK interface. It supports OMEMO encryption, group chats, file transfer, and an extensive plugin system.
- OMEMO encryption
- Plugin system
- Group chat support
- Cross-platform
MongooseIM
MongooseIM is an enterprise-grade XMPP server written in Erlang, designed for high scalability and reliability. It supports clustering, REST APIs, and modern messaging extensions.
- Built for massive scale
- Clustering and high availability
- GraphQL and REST admin APIs
- Modern XEP support
Gajim vs MongooseIM: key differences
Gajim is written in Python, while MongooseIM is built with Erlang. Licensing differs — GPL-3.0 for Gajim versus GPL-2.0 for MongooseIM. Gajim is the lighter option, starting around 128 MB of RAM against 1,024 MB for MongooseIM. Gajim is the more established project (first released 2005), while MongooseIM arrived in 2012. MongooseIM has the considerably larger community, at 1,760 GitHub stars versus 600. MongooseIM lists first-class Docker deployment; Gajim does not.
Why pick each one
Choose Gajim if…
- Released under the GPL-3.0 license
- Easy to set up — beginner-friendly
- Written in Python
- Tiny footprint — runs in 128 MB RAM
Choose MongooseIM if…
- Released under the GPL-2.0 license
- First-class Docker support for quick deployment
- Active community (1.8k GitHub stars)
- Written in Erlang
Watch out for
- Complex deployment
- Requires Erlang knowledge to extend
Frequently asked questions
Is Gajim or MongooseIM better?
Neither is universally better. MongooseIM has the larger community, while Gajim is simpler to set up (easy difficulty). Choose based on the comparison table above and your own setup.
Are Gajim and MongooseIM free and open-source?
Yes. Gajim is licensed under GPL-3.0 and MongooseIM under GPL-2.0. Both can be self-hosted at no software cost.
Can I run Gajim and MongooseIM with Docker?
Gajim: check the project docs for container support. MongooseIM: yes.
Which is lighter on resources, Gajim or MongooseIM?
Gajim has the smaller minimum footprint at 128 MB of RAM, compared to about 1,024 MB for MongooseIM. Real-world usage depends on library size, user count, and enabled features.