Delta Chat vs Session
A side-by-side comparison of two self-hosted chat & communication options — licensing, setup difficulty, resource needs, and what each one replaces.
Delta Chat
Decentralized messenger built on top of email
VS
Session
Onion-routed private messenger with no phone number
| Feature | Delta Chat | Session |
|---|---|---|
| Deploy effort | Read-the-docs project | Read-the-docs project |
| Health score | 82 · Excellent | 80 · Excellent |
| Category | Chat & Communication | Chat & Communication |
| License | MPL-2.0 | GPL-3.0 |
| Language | Rust | TypeScript |
| Setup difficulty | Medium | Medium |
| Min. RAM | 256 MB | 256 MB |
| Deployment | bare-metal, binary | bare-metal, binary, source |
| GitHub stars | ★ 929 | ★ 585 |
| First released | 2017 | 2020 |
| Replaces | WhatsApp, Signal, Telegram | Signal, WhatsApp, Telegram |
What are Delta Chat and Session?
Delta Chat
Delta Chat is a messaging app that uses standard email servers as its transport, providing chat-like UX with end-to-end encryption. Any IMAP/SMTP mail server can serve as the self-hosted backend.
- Uses existing email infrastructure
- Autocrypt end-to-end encryption
- No phone number required
- Cross-platform clients
Session
Session is an end-to-end encrypted messenger that routes messages through a decentralized onion network of community-operated nodes. It requires no phone number or email to sign up.
- Onion-routed message delivery
- No phone number required
- Decentralized service node network
- End-to-end encryption
Delta Chat vs Session: key differences
Delta Chat is written in Rust, while Session is built with TypeScript. Licensing differs — MPL-2.0 for Delta Chat versus GPL-3.0 for Session. Delta Chat is the more established project (first released 2017), while Session arrived in 2020.
Why pick each one
Choose Delta Chat if…
- Leverages decentralized email
- No new server protocol
Watch out for
- Email latency for messages
- Needs an IMAP/SMTP account
Choose Session if…
- Released under the GPL-3.0 license
- Written in TypeScript
- Tiny footprint — runs in 256 MB RAM
Watch out for
- Relies on the Session node network
- Message delivery can be slower
Frequently asked questions
Is Delta Chat or Session better?
Neither is universally better. Delta Chat has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Delta Chat and Session free and open-source?
Yes. Delta Chat is licensed under MPL-2.0 and Session under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Delta Chat and Session with Docker?
Delta Chat: check the project docs for container support. Session: check the project docs for container support.