Open Source Alternatives to Microsoft OneDrive

Switching from OneDrive to an open source alternative means leaving Microsoft’s bundled Windows/365 storage in favor of infrastructure you control. Nextcloud offers the closest equivalent — file sync and sharing alongside calendars, contacts, and in-browser document editing, self-hosted on your own server or through a hosting provider instead of Microsoft’s cloud. Syncthing is a leaner option for users who just want files kept in sync across their own devices without any central server at all, encrypting transfers directly device-to-device. Seafile is a middle path: a self-hosted server like Nextcloud, but scoped tightly to fast, block-deduplicated sync and per-library version history rather than a full groupware suite — its Community Edition is open source (AGPL-3.0), with additional enterprise features sold separately as a proprietary Professional Edition. All three remove the tight coupling to Windows and Microsoft 365 that OneDrive assumes, at the cost of the automatic desktop-folder backup and deep Office integration built into Windows itself.