Let's Chat vs Mattermost
A side-by-side comparison of two self-hosted team chat options — licensing, setup difficulty, resource needs, and what each one replaces.
Mattermost
Secure collaboration for developer teams
| Feature | Let's Chat | Mattermost |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 15 · At risk | 99 · Excellent |
| Status | Archived | Actively maintained |
| Category | Team Chat | Team Chat |
| License | MIT | AGPL-3.0 |
| Language | JavaScript | TypeScript |
| Setup difficulty | Medium | Medium |
| Min. RAM | 256 MB | 2,048 MB |
| Deployment | docker, bare-metal, source | docker, bare-metal, kubernetes |
| GitHub stars | ★ 9,797 | ★ 39,167 |
| First released | 2014 | 2016 |
| Replaces | Slack, HipChat | Slack, Microsoft Teams |
What are Let's Chat and Mattermost?
Let's Chat
Let's Chat is a persistent messaging application for small teams, offering chat rooms, file uploads, and history search. It is a lightweight Node.js application backed by MongoDB.
- Persistent chat rooms
- File uploads and image embeds
- Searchable history
- LDAP/Kerberos authentication
Mattermost
Mattermost is an open-source, self-hostable messaging platform focused on secure collaboration for technical teams. It targets organizations with privacy or compliance needs. It is deployed via Docker, packages, or Kubernetes.
- Channels, threads and search
- Strong DevOps integrations
- Self-hosted and on-prem focus
- Playbooks and boards
Let's Chat vs Mattermost: key differences
The biggest difference is maintenance: Let's Chat's repository is archived and no longer developed, while Mattermost is actively maintained. Let's Chat is written in JavaScript, while Mattermost is built with TypeScript. Licensing differs — MIT for Let's Chat versus AGPL-3.0 for Mattermost. Let's Chat is the lighter option, starting around 256 MB of RAM against 2,048 MB for Mattermost. Let's Chat is the more established project (first released 2014), while Mattermost arrived in 2016. Mattermost has the considerably larger community, at 39,167 GitHub stars versus 9,797.
Why pick each one
Choose Let's Chat if…
- Released under the MIT license
- First-class Docker support for quick deployment
- Mature project with 9.8k GitHub stars
- Written in JavaScript
Watch out for
- No longer actively developed
- Dated interface
Choose Mattermost if…
- Great for technical teams
- Strong security posture
- Good integrations
Watch out for
- Enterprise features gated
- Needs a real database
Frequently asked questions
Is Let's Chat or Mattermost better?
Neither is universally better. Mattermost has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Let's Chat and Mattermost free and open-source?
Yes. Let's Chat is licensed under MIT and Mattermost under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Let's Chat and Mattermost with Docker?
Let's Chat: yes. Mattermost: yes.
Which is lighter on resources, Let's Chat or Mattermost?
Let's Chat has the smaller minimum footprint at 256 MB of RAM, compared to about 2,048 MB for Mattermost. Real-world usage depends on library size, user count, and enabled features.