Seafile

Seafile is an open-source file sync and share platform you run on your own server instead of Dropbox or Google Drive’s data centers. It organizes files into “libraries” instead of one giant folder tree, transfers only the pieces of a file that actually changed instead of re-uploading the whole thing, and can encrypt individual libraries with a password Seafile itself never sees.

What Seafile actually does

Seafile has been developed by Seafile Ltd. since 2012, and it’s built with a different philosophy than Nextcloud or ownCloud. Instead of a PHP application bolted onto a shared filesystem, Seafile’s server core is written in C, and syncing works closer to a distributed version-control system than a folder-mirroring tool: every library keeps its own file history, and the client only ever sends the data blocks that changed, not a fresh copy of the whole file. That’s why Seafile has a reputation for handling large libraries, flaky connections, and resumed transfers noticeably better than file-by-file sync tools.

License: Community Edition vs. Professional Edition. Seafile’s server core (haiwen/seafile-server on GitHub) is released under AGPL-3.0, confirmed directly in the project’s LICENSE.txt (with an added permission to link against OpenSSL). That’s the free, open-source Community Edition (CE) this fiche covers, and it has no artificial limit on users or storage.

Seafile Ltd. separately sells a closed-source Professional Edition (Pro/EE) built on the same core: LDAP/AD sync, single sign-on (ADFS, Shibboleth), audit logs, two-factor authentication, remote wipe, antivirus integration, online garbage collection, and S3/Ceph storage backends are Pro-only features, absent from CE. Pro is free for up to 3 users with no license file needed, then billed per user per year (roughly $48/user for 10-249 users at the time of writing). For a homelab or small household, CE covers every sync, sharing, versioning, and encryption feature that matters; Pro buys enterprise account management, not more storage or sync capability.

Core features

Libraries instead of folders: each library syncs independently, can be shared into groups with its own permissions, and keeps a version history you can roll back file by file.
Optional client-side encryption: any library can be encrypted with a password chosen by the user. The desktop client encrypts data before it leaves the device, so the server (and anyone who compromises it) never sees plaintext or the password itself.
Block-level differential sync: files are split into content-addressed blocks; only changed blocks transfer, interrupted uploads resume instead of restarting, and identical blocks across files are deduplicated on disk.
Desktop, mobile, and drive clients: native sync clients for Windows, macOS, and Linux with selective folder sync; iOS and Android apps; and a virtual-drive client that streams files on demand instead of syncing an entire library to local disk.
Sharing and collaboration: password-protected download links, upload links for accepting files from people without an account, and group-based sharing between users.

Installing Seafile with Docker Compose

Seafile Ltd. maintains an official Docker image, seafileltd/seafile-mc, documented in the official Docker deployment manual. The stack needs a MariaDB database and a Memcached instance alongside the Seafile container itself; a minimal docker-compose.yml looks like this:

services:
  db:
    image: mariadb:10.11
    environment:
      - MYSQL_ROOT_PASSWORD=change_me_root_pw
    volumes:
      - /opt/seafile-mysql/db:/var/lib/mysql
    restart: unless-stopped

  memcached:
    image: memcached:1.6.29
    entrypoint: memcached -m 256
    restart: unless-stopped

  seafile:
    image: seafileltd/seafile-mc:13.0.25
    ports:
      - "80:80"
    volumes:
      - /opt/seafile-data:/shared
    environment:
      - DB_ROOT_PASSWD=change_me_root_pw
      - SEAFILE_ADMIN_EMAIL=admin@example.com
      - SEAFILE_ADMIN_PASSWORD=change_me_admin_pw
      - SEAFILE_SERVER_HOSTNAME=seafile.example.com
    depends_on:
      - db
      - memcached
    restart: unless-stopped

Bring it up with docker compose up -d, wait a few minutes for first-run initialization, then open the hostname in a browser to reach the Seahub web UI. Configuration and logs persist under /opt/seafile-data; that’s the directory to back up, alongside a database dump.

Hardware: Seafile’s C-based server core is noticeably lighter than Nextcloud’s PHP stack at idle. A single low-power box or VM with 2 vCPUs and 2-4GB of RAM handles a personal or small-household deployment comfortably; scale up RAM and switch to SSD storage as library size and concurrent sync clients grow. As with any file-sync service, put it behind a reverse proxy with a real TLS certificate rather than forwarding raw ports to the container.

Prerequisites

You’ll need Docker and Docker Compose installed on a Linux host, a domain or subdomain pointing at that host if you want a proper certificate, and a reverse proxy (Nginx Proxy Manager, Caddy, Traefik) or a Tailscale/VPN setup if you don’t want to expose Seafile directly to the internet. Nothing here is Seafile-specific; it’s the same baseline any self-hosted web app needs.

Seafile vs. the alternatives

Seafile and Nextcloud get compared constantly because they solve overlapping problems from opposite directions. Nextcloud is a full platform: files, calendar, contacts, chat, and office editing under one login, at the cost of a heavier server and a more sprawling attack surface. Seafile stays narrowly focused on sync and share, and does that one job faster and lighter.

Faster, more efficient sync on large libraries and unreliable connections, thanks to block-level differential transfer
Real client-side encryption on any library you choose, not just at-rest disk encryption
Noticeably lighter server footprint than Nextcloud, easier to run on modest hardware

No built-in calendar, contacts, chat, or office suite; Seafile is sync and share only, not an all-in-one platform
Web UI and mobile apps are functional but less polished than Nextcloud’s
Genuinely useful admin features (LDAP/AD sync, SSO, audit logs, antivirus, online GC) are locked behind the paid Pro edition

Against Dropbox or Google Drive, it’s the usual self-hosting trade-off: no subscription and files that never leave hardware you control, in exchange for handling your own backups, updates, and uptime. Against ownCloud, the two projects have diverged since Nextcloud’s 2016 fork the same way Nextcloud itself did; ownCloud today leans enterprise, while Seafile stays a lean, single-purpose sync tool. If all you want is folder sync between a few machines with no server at all, Syncthing is worth a look too, though it skips the web UI, sharing links, and encrypted-library model Seafile provides.

Official resources

FAQ

Is Seafile actually free?

Yes, the Community Edition is free and open source under AGPL-3.0, with no cap on users or storage. The Professional Edition is a separate, paid product for organizations that need LDAP/SSO, audit logs, and similar enterprise controls.

Seafile or Nextcloud, which one should I run?

Pick Nextcloud if you want calendar, contacts, chat, and office editing alongside file sync in one app. Pick Seafile if file sync and sharing is the actual job, and you’d rather it be fast, light on resources, and support real client-side encryption.

Does Seafile support two-factor authentication?

Two-factor authentication is listed as a Professional Edition feature, not part of the free Community Edition. Put Seafile behind a reverse proxy that supports its own authentication layer, or a VPN like Tailscale, if you want a second factor on a CE deployment.

Do I need Docker to run Seafile?

No, but it’s the path most homelabbers take and the one Seafile Ltd. documents in the most detail. Seafile also installs directly on Linux from source or distro packages, per the official manual, if you’d rather skip containers entirely.