Self-Hosting Matrix with Element: Decentralized Chat You Actually Control

Your team's on Slack, your gaming friends are on Discord, your family uses WhatsApp, and your open source community is on IRC. Each platform owns your messages, each can read them, and each locks you into their ecosystem. If Slack decides to delete messages older than 90 days on the free tier (they did), you lose your history.

Matrix is an open standard for decentralized communication. You run your own server, you own your data, and you can still talk to people on other Matrix servers — or bridge to Slack, Discord, WhatsApp, and more.

How Matrix Works

Matrix is a protocol, not a single service. Here's the architecture:

• Homeserver: Your server that stores your messages and syncs with other servers (like email servers sync with each other)
• Client: The app you use to chat (Element is the most popular)
• Federation: Your server can talk to any other Matrix server, so @alice:yourserver.com can message @bob:matrix.org
• Bridges: Connect Matrix to other platforms (Slack, Discord, WhatsApp, IRC, Signal)

Think of it like email: you can run your own email server and still send messages to Gmail users. Matrix works the same way for chat.

Matrix vs. The Alternatives

Choosing a Homeserver

Synapse (Reference Implementation)

Synapse is the original Matrix homeserver written in Python. It's the most feature-complete and widely deployed.

services:
  synapse:
    image: matrixdotorg/synapse:latest
    restart: unless-stopped
    volumes:
      - synapse_data:/data
    environment:
      SYNAPSE_SERVER_NAME: matrix.yourdomain.com
      SYNAPSE_REPORT_STATS: "no"
    ports:
      - 8008:8008

  postgres:
    image: postgres:16-alpine
    restart: unless-stopped
    volumes:
      - synapse_db:/var/lib/postgresql/data
    environment:
      POSTGRES_DB: synapse
      POSTGRES_USER: synapse
      POSTGRES_PASSWORD: changeme
      POSTGRES_INITDB_ARGS: "--encoding=UTF-8 --lc-collate=C --lc-ctype=C"

volumes:
  synapse_data:
  synapse_db:

Generate the initial config:

docker run --rm \
  -v synapse_data:/data \
  -e SYNAPSE_SERVER_NAME=matrix.yourdomain.com \
  -e SYNAPSE_REPORT_STATS=no \
  matrixdotorg/synapse:latest generate

Pros: Full feature support, most bridges work best with it, large community. Cons: Resource-hungry (1-2 GB RAM minimum), Python performance, database can grow large.

Conduit (Lightweight Alternative)

Conduit is a Matrix homeserver written in Rust. It's fast, lightweight, and simple to configure.

services:
  conduit:
    image: matrixconduit/matrix-conduit:latest
    restart: unless-stopped
    ports:
      - 6167:6167
    volumes:
      - conduit_data:/var/lib/matrix-conduit
    environment:
      CONDUIT_SERVER_NAME: matrix.yourdomain.com
      CONDUIT_DATABASE_BACKEND: rocksdb
      CONDUIT_PORT: 6167
      CONDUIT_MAX_REQUEST_SIZE: 20000000
      CONDUIT_ALLOW_REGISTRATION: "false"
      CONDUIT_ALLOW_FEDERATION: "true"
      CONDUIT_TRUSTED_SERVERS: '["matrix.org"]'

volumes:
  conduit_data:

Pros: ~10 MB RAM, single binary, embedded database (no Postgres needed), fast. Cons: Missing some advanced features, fewer bridges tested, smaller community.

For most self-hosters: Start with Conduit if you want a personal/family server. Use Synapse if you need bridges or are running a community.

Setting Up Element Web

Element is the primary Matrix client. Host it alongside your homeserver:

services:
  element:
    image: vectorim/element-web:latest
    restart: unless-stopped
    ports:
      - 8080:80
    volumes:
      - ./element-config.json:/app/config.json:ro

element-config.json:

{
  "default_server_config": {
    "m.homeserver": {
      "base_url": "https://matrix.yourdomain.com",
      "server_name": "yourdomain.com"
    }
  },
  "brand": "Element",
  "default_theme": "dark",
  "room_directory": {
    "servers": ["yourdomain.com", "matrix.org"]
  }
}

Element is also available as a desktop app (Electron) and mobile apps (iOS/Android) — point them at your homeserver URL.

Federation: Talking to Other Servers

Federation requires proper DNS and reverse proxy setup.

DNS Records

_matrix._tcp.yourdomain.com. 3600 IN SRV 10 5 443 matrix.yourdomain.com.

Or use a .well-known file. Serve this at https://yourdomain.com/.well-known/matrix/server:

{
  "m.server": "matrix.yourdomain.com:443"
}

And at https://yourdomain.com/.well-known/matrix/client:

{
  "m.homeserver": {
    "base_url": "https://matrix.yourdomain.com"
  }
}

Reverse Proxy (Caddy example)

matrix.yourdomain.com {
    reverse_proxy /_matrix/* synapse:8008
    reverse_proxy /_synapse/* synapse:8008
}

chat.yourdomain.com {
    reverse_proxy element:80
}

Test federation at federationtester.matrix.org — it'll check your DNS and connectivity.

Bridges: Connecting Other Platforms

Bridges are Matrix's superpower. They let you interact with other chat platforms through your Matrix client.

Popular Bridges

Example: Discord Bridge

services:
  mautrix-discord:
    image: dock.mau.dev/mautrix/discord:latest
    restart: unless-stopped
    volumes:
      - discord_bridge:/data

volumes:
  discord_bridge:

After starting, generate a config with docker exec, edit it to point at your homeserver, register the appservice with Synapse, and log in with your Discord token. Your Discord DMs and servers appear as Matrix rooms.

The result: You can read and reply to Slack, Discord, and WhatsApp messages all from Element. One client for everything.

End-to-End Encryption

Matrix supports end-to-end encryption (E2EE) using the Olm/Megolm protocols (the same cryptographic design Signal uses).

• DMs: Encrypted by default
• Group chats: Optional, can be enabled per room
• Key backup: Set up cross-signing and key backup so you don't lose message history when adding new devices

Important: E2EE means your server can't read message contents. This is great for privacy but means server-side search only works on unencrypted rooms.

Performance Tuning for Synapse

If you go with Synapse, these settings matter:

homeserver.yaml:

# Use PostgreSQL, not SQLite
database:
  name: psycopg2
  args:
    database: synapse
    user: synapse
    password: changeme
    host: postgres

# Limit federation (if you don't need it)
# federation_domain_whitelist:
#   - matrix.org

# Media storage limits
max_upload_size: 50M
url_preview_enabled: true

Resource expectations for Synapse:

• Small (1-5 users, no bridges): 512 MB RAM
• Medium (5-50 users, some bridges): 1-2 GB RAM
• Large (50+ users, many bridges, federation): 4+ GB RAM

Common Pitfalls

• Synapse database growth: Media and message history accumulate. Set up the Synapse Admin API to purge old remote media.
• Federation debugging: Use the Matrix Federation Tester. 90% of federation issues are DNS or reverse proxy misconfigs.
• Bridge maintenance: Bridges need updating separately from the homeserver. Pin versions and update deliberately.
• Key verification: Educate your users about cross-signing verification. Without it, E2EE provides weaker guarantees.

The Bottom Line

Matrix gives you a Slack/Discord-quality chat experience that you fully own and control. Federation means you're not isolated — you can talk to anyone on the Matrix network. Bridges mean you can consolidate all your chat platforms into one client.

The tradeoff is complexity. Synapse is heavier than most self-hosted apps, bridges require per-platform setup, and federation needs proper DNS configuration. But for anyone serious about owning their communications, Matrix is the strongest option available.