Seafile

Seafile is a self-hosted file sync and share platform focused on performance and encryption. It organises files into libraries, syncs them to desktop and mobile clients using a delta-sync algorithm, and gives you per-library control over sharing and encryption settings.

The key distinction from Nextcloud is scope and speed. Seafile is a focused file sync tool. Nextcloud is a full groupware platform. For users who want the fastest possible file sync with strong encryption and are not interested in calendar, contacts, tasks, or dozens of apps, Seafile delivers that without the overhead.

Client-side encryption can be enabled per library. When turned on, files are encrypted before they leave your device and the server stores only ciphertext — even the server administrator cannot read the contents. This makes Seafile viable for storing genuinely sensitive documents in a cloud or shared server environment.

Sharing permissions are granular: read/write, read-only, and preview-only access can be set per folder, with optional password protection and link expiry. File versioning and a trash recovery system protect against accidental deletion or overwrites.

The community edition is free and covers the core use case. Enterprise features including SSO, audit logging, and compliance controls require a paid licence. For a small team or personal use, the community edition is fully functional and the performance advantage over heavier alternatives is noticeable in everyday use.