Nextcloud Files vs Seafile vs Syncthing: Best Self-Hosted File Sync 2026

Dropbox, Google Drive, and OneDrive have trained us to expect seamless file synchronization across devices. But every file you upload to a third-party cloud is a file you no longer fully control. For individuals and organizations that care about data sovereignty, privacy, and long-term access, self-hosted file sync is no longer a luxury — it’s a necessity.

In 2026, the three most mature and widely adopted self-hosted file sync solutions are nextcloud FisyncthingSeafile, and Syncthing. They take fundamentally different approaches to the same problem, and choosing the right one depends on your priorities. This guide compares all three sidockerside, with complete Docker deployment instructions, so you can pick the best fit and get it running in under ten minutes.

Why Self-Host Your File Sync and Sharing

The business model of commercial cloud storage is straightforward: you pay a monthly fee, and in return, a corporation stores, processes, and controls access to your data. Even with encryption in transit and at rest, the provider holds the decryption keys. They can scan your files, comply with data requests, change their pricing, or shut down your account.

Self-hosting file sync flips that relationship:

• Full data ownership: Your files live on hardware you control. No one else has access.
• No subscription creep: Pay for storage once, not every month forever.
• Compliance and auditing: Required for healthcare, legal, and financial organizations handling sensitive data.
• Customizable workflows: Integrate with your existing authentication, backup, and monitoring infrastructure.
• No vendor lock-in: Migrate or change providers on your own terms.

The trade-off is operational responsibility: you maintain the server, manage backups, and handle updates. The good news is that Docker makes this straightforward. Let’s look at the three leading options.

Architecture at a Glance

The fundamental difference between these three tools is their architecture. Understanding this is the single most important factor in choosing the right one.

Nextcloud Files: The All-in-One Platform

Nextcloud is a full-featured cloud productivity suite. Its file sync component is one module within a much larger ecosystem that includes calendars, contacts, video calls, office suites, mail, and thousands of community apps. Files are stored on the server’s filesystem and accessed via WebDAV. Desktop and mobile clients handle synchronization.

Nextcloud Files works best when you want a complete cloud platform, not just file sync. If you’re already running Nextcloud for calendars or contacts, adding file sync is a natural extension.

Seafile: Performance-Focused File Sync

Seafile was built from the ground up as a high-performance file synchronization and sharing platform. It stores files in a proprietary block-based format (similar to Git’s object model) rather than as individual files on disk. This enables efficient deduplication, versioning, and delta sync — only changed blocks are transferred, not entire files.

Seafile is the best choice when raw sync performance and large file handling are your top priorities. It consistently outperforms Nextcloud in speed tests, especially with large libraries and many concurrent users.

Syncthing: Peer-to-Peer, No Server Required

Syncthing takes a radically different approach. There is no central server. Devices sync directly with each other using a peer-to-peer protocol built on the Block Exchange Protocol (BEP). Each device holds a complete copy of the synchronized folders, and changes propagate through the mesh as devices come online.

Syncthing is ideal when you want maximum simplicity and zero server maintenance. Set up two devices, connect them, and they sync. No Docker, no database, no reverse proxy — just direct device-to-device communication.

Feature Comparison Table

Nextcloud Files: Complete Docker Setup

Nextcloud is the most feature-rich option, but it requires the most infrastructure. A production deployment needs a web server, PHP runtime, database, and optionally Redis for caching.

Prerequisites

• A Linux server with at least 2 GB RAM (4 GB recommended)
• Docker and Docker Compose installed
• A domain name with DNS pointing to your server
• SSL certificates (Let’s Encrypt via Caddy or Traefik)

Docker Compose Configuration

Create a directory for your Nextcloud deployment:

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mkdir -p ~/nextcloud && cd ~/nextcloud

Create docker-compose.yml:

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version: '3.8'

services:
  db:
    image: mariadb:11
    restart: always
    command: --transaction-isolation=READ-COMMITTED --binlog-format=ROW
    volumes:
      - db_data:/var/lib/mysql
    environment:
      - MYSQL_ROOT_PASSWORD=nextcloud_root_password
      - MYSQL_PASSWORD=nextcloud_password
      - MYSQL_DATABASE=nextcloud
      - MYSQL_USER=nextcloud
    healthcheck:
      test: ["CMD", "healthcheck.sh", "--connect", "--innodb_initialized"]
      interval: 10s
      timeout: 5s
      retries: 5

  redis:
    image: redis:7-alpine
    restart: always
    volumes:
      - redis_data:/data
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 10s
      timeout: 5s
      retries: 5

  app:
    image: nextcloud:30-apache
    restart: always
    ports:
      - "8080:80"
    volumes:
      - nextcloud_data:/var/www/html
      - ./custom_apps:/var/www/html/custom_apps
      - ./config:/var/www/html/config
      - ./data:/var/www/html/data
      - ./themes:/var/www/html/themes
    environment:
      - MYSQL_HOST=db
      - MYSQL_PASSWORD=nextcloud_password
      - MYSQL_DATABASE=nextcloud
      - MYSQL_USER=nextcloud
      - REDIS_HOST=redis
      - NEXTCLOUD_ADMIN_USER=admin
      - NEXTCLOUD_ADMIN_PASSWORD=your_admin_password
      - NEXTCLOUD_TRUSTED_DOMAINS=files.example.com
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_healthy

  cron:
    image: nextcloud:30-apache
    restart: always
    volumes:
      - nextcloud_data:/var/www/html
      - ./data:/var/www/html/data
    entrypoint: /cron.sh
    depends_on:
      - db
      - redis

volumes:
  db_data:
  redis_data:
  nextcloud_data:

Reverse Proxy with Caddy

For HTTPS, the simplest approach is Caddy:

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mkdir -p ~/nextcloud/caddy && cd ~/nextcloud/caddy

Create Caddyfile:

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files.example.com {
    reverse_proxy app:8080

    header {
        Strict-Transport-Security "max-age=31536000; includeSubDomains; preload"
        Referrer-Policy "no-referrer"
        X-Content-Type-Options "nosniff"
        X-Frame-Options "DENY"
    }

    # Allow large file uploads
    @largefiles path_regexp \.mp4$|\.mkv$|\.zip$|\.tar\.gz$
    handle @largefiles {
        request_body {
            max_size 2GB
        }
    }
}

Run Caddy alongside your compose stack:

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  caddy:
    image: caddy:2-alpine
    restart: always
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./Caddyfile:/etc/caddy/Caddyfile
      - caddy_data:/data
      - caddy_config:/config
    depends_on:
      - app

volumes:
  caddy_data:
  caddy_config:

Post-Installation Tuning

After the initial setup through the web interface, apply these optimizations:

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# Enter the app container
docker compose exec app bash

# Enable recommended apps
occ app:enable files_external
occ app:enable files_trashbin
occ app:enable files_versions

# Set background jobs to cron (already handled by cron service)
occ background:cron

# Configure file locking with Redis
occ config:system:set filelocking.enabled --value=true
occ config:system:set memcache.locking --value="\OC\Memcache\Redis"

# Add trusted proxies if behind a reverse proxy
occ config:system:set trusted_proxies 0 --value="172.16.0.0/12"

Desktop Client Installation

Nextcloud desktop clients are available for all major platforms:

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# Ubuntu/Debian
sudo apt install nextcloud-desktop

# Fedora
sudo dnf install nextcloud-client

# macOS
brew install --cask nextcloud

# Windows — download from nextcloud.com/install

On first launch, enter your server URL (https://files.example.com), authenticate, and select which folders to sync. The client supports selective sync, virtual files (on-demand download), and bandwidth throttling.

Seafile: Complete Docker Setup

Seafile’s setup is leaner than Nextcloud’s. The community edition handles everything a typical user or small team needs.

Prerequisites

• A Linux server with at least 1 GB RAM
• Docker and Docker Compose installed
• A domain name pointing to your server

Docker Compose Configuration

Seafile provides an official Docker image that bundles the web server, Seahub (web UI), and Seafile server into a single container:

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mkdir -p ~/seafile && cd ~/seafile
mkdir -p shared/seafile-data shared/seahub-data

Create docker-compose.yml:

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version: '3.8'

services:
  db:
    image: mariadb:11
    restart: always
    command: --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci
    volumes:
      - db_data:/var/lib/mysql
    environment:
      - MYSQL_ROOT_PASSWORD=seafile_root_password
      - MYSQL_LOG_CONSOLE=true
      - MARIADB_AUTO_UPGRADE=1
    healthcheck:
      test: ["CMD", "healthcheck.sh", "--connect", "--innodb_initialized"]
      interval: 10s
      timeout: 5s
      retries: 5

  memcached:
    image: memcached:1.6-alpine
    restart: always
    entrypoint: memcached -m 256
    healthcheck:
      test: ["CMD", "nc", "-z", "localhost", "11211"]
      interval: 10s
      timeout: 5s
      retries: 5

  seafile:
    image: seafileltd/seafile-mc:latest
    restart: always
    ports:
      - "8080:80"
      - "8443:443"
    volumes:
      - ./shared/seafile-data:/shared
    environment:
      - DB_HOST=db
      - DB_ROOT_PASSWD=seafile_root_password
      - SEAFILE_ADMIN_EMAIL=admin@example.com
      - SEAFILE_ADMIN_PASSWORD=your_admin_password
      - SEAFILE_SERVER_LETSENCRYPT=false
      - SEAFILE_SERVER_HOSTNAME=files.example.com
    depends_on:
      db:
        condition: service_healthy
      memcached:
        condition: service_healthy

Seafile Nginx Reverse Proxy

Seafile’s internal Nginx handles its own SSL, but if you prefer a separate reverse proxy:

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  nginx:
    image: nginx:alpine
    restart: always
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
      - ./certs:/etc/nginx/certs:ro
    depends_on:
      - seafile

Create nginx.conf:

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events {
    worker_connections 1024;
}

http {
    upstream seafile {
        server seafile:80;
    }

    server {
        listen 80;
        server_name files.example.com;
        return 301 https://$host$request_uri;
    }

    server {
        listen 443 ssl http2;
        server_name files.example.com;

        ssl_certificate     /etc/nginx/certs/fullchain.pem;
        ssl_certificate_key /etc/nginx/certs/privkey.pem;

        client_max_body_size 0;

        location / {
            proxy_pass http://seafile;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Host $server_name;
            proxy_read_timeout 1200s;
        }

        location /seafhttp {
            rewrite ^/seafhttp(.*)$ $1 break;
            proxy_pass http://seafile:8082;
            client_max_body_size 0;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_connect_timeout 36000s;
            proxy_read_timeout 36000s;
            proxy_send_timeout 36000s;
            send_timeout 36000s;
        }

        location /seafdav {
            proxy_pass http://seafile:8080/seafdav;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Host $server_name;
            proxy_set_header X-Forwarded-Proto $scheme;
            client_max_body_size 0;
            fastcgi_read_timeout 36000s;
            proxy_read_timeout 36000s;
            proxy_send_timeout 36000s;
        }
    }
}

Start the stack:

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docker compose up -d

Seafile will initialize its databases on first run. This takes about 30 seconds. Check the logs:

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docker compose logs -f seafile

Look for the message “seafile server is running” to confirm successful startup.

Seafile Desktop Client

The Seafile desktop client is separate from the web interface and provides local file synchronization:

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# Ubuntu/Debian — add Seafile PPA
sudo add-apt-repository ppa:seafile/seafile
sudo apt update
sudo apt install seafile-gui

# macOS
brew install --cask seafile-client

# Arch Linux
sudo pacman -S seafile-client

The Seafile client works with libraries rather than arbitrary folders. Each library is a self-contained sync unit with its own encryption, sharing settings, and version history.

Enabling WebDAV in Seafile

Seafile supports WebDAV out of the box, but it must be enabled in the configuration:

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# Edit seafdav.conf inside the container
docker compose exec seafile vi /shared/seafile/conf/seafdav.conf

Set the following:

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[WEBDAV]
enabled = true
port = 8080
fastcgi = false
share_name = /seafdav

Restart the Seafile service:

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docker compose restart seafile

WebDAV is now accessible at https://files.example.com/seafdav. This is useful for mounting Seafile libraries as network drives or integrating with third-party applications.

Syncthing: Complete Setup

Syncthing has no central server, no database, and no web application. It runs as a background process on each device and syncs folders peer-to-peer.

Prerequisites

• Two or more devices (any combination of Linux, macOS, Windows, or Android)
• Network connectivity between devices (or configured relay/relaying)

Installing Syncthing on Linux

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# Add the official Syncthing repository (Debian/Ubuntu)
sudo curl -fsSL https://syncthing.net/release-key.txt \
  -o /etc/apt/keyrings/syncthing-archive-keyring.gpg

echo "deb [signed-by=/etc/apt/keyrings/syncthing-archive-keyring.gpg] \
  https://apt.syncthing.net/ syncthing stable" | \
  sudo tee /etc/apt/sources.list.d/syncthing.list

sudo apt update
sudo apt install syncthing

# Enable and start the systemd service for your user
systemctl --user enable syncthing
systemctl --user start syncthing

Installing Syncthing via Docker

For containerized deployments or multi-user setups:

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mkdir -p ~/syncthing/config ~/syncthing/data

Create docker-compose.yml:

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version: '3.8'

services:
  syncthing:
    image: syncthing/syncthing:latest
    restart: always
    ports:
      - "8384:8384"   # Web UI
      - "22000:22000/tcp"  # TCP sync
      - "22000:22000/udp"  # QUIC sync
      - "21027:21027/udp"  # Local discovery
    volumes:
      - ./config:/var/syncthing/config
      - ./data:/var/syncthing/data
    environment:
      - PUID=1000
      - PGID=1000
    devices:
      - /dev/inotify:/dev/inotify

Start the container:

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docker compose up -d

Initial Configuration

Syncthing’s web GUI runs on port 8384. On first access, it generates a unique Device ID (a long cryptographic identifier) and a GUI admin password.

1. Open http://your-server:8384 in a browser
2. Set a GUI admin password under Actions > Settings > GUI
3. Note your Device ID (Actions > Show ID)
4. On the second device, go to Actions > Show ID and note its Device ID
5. On each device, click Add Remote Device and enter the other device’s ID
6. Accept the device pairing request on both sides
7. Share a folder from one device and accept it on the other

Syncthing with Mutual TLS (Advanced)

For production deployments between untrusted networks, enable mutual TLS authentication:

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<!-- Edit ~/.config/syncthing/config.xml -->
<gui enabled="true" tls="true" debugging="false">
    <address>0.0.0.0:8384</address>
    <apikey>your-api-key</apikey>
    <user>admin</user>
    <password>your-hashed-password</password>
</gui>

<options>
    <listenAddress>default</listenAddress>
    <globalAnnounceServer>default</globalAnnounceServer>
    <natEnabled>true</natEnabled>
    <localAnnounceEnabled>true</localAnnounceEnabled>
    <urAccepted>0</urAccepted>
    <autoUpgradeIntervalH>12</autoUpgradeIntervalH>
</options>

Syncthing Discovery and Relaying

Syncthing uses two infrastructure components to help devices find each other:

• Global Discovery Servers: Public servers that help devices locate each other across NATs and firewalls. Free and provided by the Syncthing project.
• Relay Servers: When direct connection is impossible, traffic routes through a public relay. You can also run your own:

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docker run -d --name syncthing-relay \
  -p 22067:22067 \
  -p 22070:22070 \
  syncthing/relaysrv:latest

Syncing Multiple Devices

Syncthing scales naturally to any number of devices. Add a third device by exchanging Device IDs as before. For larger deployments, consider these patterns:

• Star topology: One central device (e.g., NAS) syncs with all others. Good for backup scenarios.
• Mesh topology: Every device syncs with every other device. Maximum redundancy but higher bandwidth.
• Hub and spoke: Groups of devices share different folder sets. Useful for team environments.

Performance Comparison

Performance is where the architectural differences become most visible.

Small Files (thousands of files, < 1 MB each)

Large Files (single file, 1-10 GB)

Seafile’s block-based storage model gives it a significant advantage with large files and frequent modifications. When you edit a 4 GB video file, Seafile only transfers the changed blocks, while Nextcloud re-uploads the entire file.

When to Choose Each Solution

Choose Nextcloud Files If:

• You want a complete cloud platform beyond file sync (calendars, contacts, mail, office editing, talk)
• Your organization already uses LDAP/Active Directory and wants SSO integration
• You need external storage mounting (S3, FTP, SMB, other WebDAV servers)
• You want collaborative document editing with Collabora or OnlyOffice
• You value a rich plugin ecosystem with 200+ community apps
• You need file drop (upload links without accounts) and advanced sharing permissions

Nextcloud is the most versatile option. It’s not the fastest at pure file sync, but it’s the only one that replaces an entire Google Workspace stack.

Choose Seafile If:

• Sync speed is your primary concern — Seafile is consistently the fastest
• You work with large files (video, CAD, disk images) and need delta sync
• You need library-level encryption where the server never sees your decryption keys
• You want file versioning and trash built in without additional apps
• You run a team or organization and need professional file sharing with fine-grained permissions
• You need WebDAV support alongside native sync for maximum compatibility

Seafile is the performance champion. It handles large file libraries and concurrent users better than any other self-hosted option.

Choose Syncthing If:

• You want zero server maintenance — no database, no web server, no updates to manage
• You only need to sync between a handful of personal devices
• You prefer peer-to-peer architecture with no central point of failure
• You want to sync directories that already exist without importing them into a library system
• You need cross-platform sync for IoT devices, Raspberry Pis, or headless servers
• You value simplicity above all else — install, pair devices, done

Syncthing is the simplest option by a wide margin. It’s not a cloud replacement — it’s a synchronization tool. There’s no web file browser, no user accounts, no sharing links. Just reliable, encrypted file sync between devices you control.

Backup Strategies for All Three

No self-hosted solution is complete without backups. Here are the recommended approaches:

Nextcloud Backup

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#!/bin/bash
# Backup script for Nextcloud
BACKUP_DIR="/backup/nextcloud/$(date +%Y%m%d)"
mkdir -p "$BACKUP_DIR"

# Maintenance mode
docker compose exec app occ maintenance:mode --on

# Database dump
docker compose exec db mysqldump -u nextcloud -pnextcloud_password nextcloud \
  > "$BACKUP_DIR/nextcloud-db.sql"

# Data directory
rsync -a ~/nextcloud/data/ "$BACKUP_DIR/data/"

# Config
cp -r ~/nextcloud/config/ "$BACKUP_DIR/config/"

# Disable maintenance mode
docker compose exec app occ maintenance:mode --off

# Keep last 7 days
find /backup/nextcloud/ -maxdepth 1 -mtime +7 -exec rm -rf {} \;

Seafile Backup

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#!/bin/bash
# Backup script for Seafile
BACKUP_DIR="/backup/seafile/$(date +%Y%m%d)"
mkdir -p "$BACKUP_DIR"

# Database dumps
docker compose exec db mysqldump -u root -pseafile_root_password \
  ccnet-db seafile-db seahub-db > "$BACKUP_DIR/seafile-all-dbs.sql"

# Seafile data (block storage + configuration)
rsync -a ~/seafile/shared/ "$BACKUP_DIR/seafile-data/"

# Keep last 14 days
find /backup/seafile/ -maxdepth 1 -mtime +14 -exec rm -rf {} \;

Syncthing Backup

Syncthing doesn’t need a central backup because every device is a backup. However, you should still:

1. Enable file versioning in Syncthing’s folder settings (Trash Can or Staggered File Versioning)
2. Back up the configuration directory (~/.config/syncthing/ or the Docker config volume)
3. Use an external backup tool like Restic or Borg for disaster recovery

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# Backup Syncthing config with Restic
restic backup ~/.config/syncthing/config.xml \
  --tag syncthing-config \
  --exclude='*.log'

Combining Solutions

There’s no rule saying you can only use one. Many homelab operators run complementary setups:

• Syncthing + Seafile: Use Syncthing for real-time device-to-device sync of working files, and Seafile as the central archive with version history and web access.
• Nextcloud + Syncthing: Run Nextcloud as your cloud platform for sharing and collaboration, and use Syncthing to sync your Nextcloud data directory across multiple storage nodes for redundancy.
• Seafile + Restic: Use Seafile for active file sync and sharing, and back up the Seafile data directory with Restic to an offsite location for disaster recovery.

Conclusion

The best self-hosted file sync solution depends on your specific needs:

• Nextcloud Files is the Swiss Army knife — not the fastest at any one thing, but it does everything well and replaces multiple cloud services.
• Seafile is the speed demon — purpose-built for fast, reliable file synchronization with excellent support for large files and team collaboration.
• Syncthing is the minimalist — zero infrastructure, zero maintenance, pure peer-to-peer file sync that just works.

All three are open source, actively maintained, and production-ready. Start with the one that matches your priorities, and don’t hesitate to combine them as your needs evolve. The beauty of self-hosting is that you’re not locked into any single vendor’s ecosystem — you can experiment, migrate, and optimize without asking permission.

Frequently Asked Questions (FAQ)

Which one should I choose in 2026?

The best choice depends on your specific requirements:

• For beginners: Start with the simplest option that covers your core use case
• For production: Choose the solution with the most active community and documentation
• For teams: Look for collaboration features and user management
• For privacy: Prefer fully open-source, self-hosted options with no telemetry

Refer to the comparison table above for detailed feature breakdowns.

Can I migrate between these tools?

Most tools support data import/export. Always:

1. Backup your current data
2. Test the migration on a staging environment
3. Check official migration guides in the documentation

Are there free versions available?

All tools in this guide offer free, open-source editions. Some also provide paid plans with additional features, priority support, or managed hosting.

How do I get started?

1. Review the comparison table to identify your requirements
2. Visit the official documentation (links provided above)
3. Start with a Docker Compose setup for easy testing
4. Join the community forums for troubleshooting