Chatmail Relay vs Session
A side-by-side comparison of two self-hosted chat & communication options — licensing, setup difficulty, resource needs, and what each one replaces.
Not the right match-up?
Chatmail Relay
Minimal email server tuned for Delta Chat messaging
VS
Session
Onion-routed private messenger with no phone number
| Feature | Chatmail Relay | Session |
|---|---|---|
| Category | Chat & Communication | Chat & Communication |
| License | MPL-2.0 | GPL-3.0 |
| Language | Python | TypeScript |
| Setup difficulty | Medium | Medium |
| Min. RAM | 512 MB | 256 MB |
| Deployment | docker, bare-metal | bare-metal, binary, source |
| GitHub stars | ★ 476 | ★ 546 |
| First released | 2023 | 2020 |
| Replaces | WhatsApp, Signal | Signal, WhatsApp, Telegram |
Why pick each one
Choose Session if…
- Released under the GPL-3.0 license
- Written in TypeScript
- Tiny footprint — runs in 256 MB RAM
Frequently asked questions
Is Chatmail Relay or Session better?
Neither is universally better. Session has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Chatmail Relay and Session free and open-source?
Yes. Chatmail Relay is licensed under MPL-2.0 and Session under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Chatmail Relay and Session with Docker?
Chatmail Relay: yes. Session: check the project docs for container support.