Open source file storage and sync tools

Four kinds of tool

The tools here solve related but different problems, and the right one depends on which you have.

• Sync-and-share platforms replace Dropbox, Google Drive or OneDrive for a household or an organization: a server with user accounts, a web interface, desktop and mobile sync clients, share links and version history. Nextcloud, Seafile, ownCloud Infinite Scale, OpenCloud, ownCloud Classic, Sync-in and Pydio Cells belong here.
• End-to-end encrypted drives do the same job while hiding data from the server itself. Peergos encrypts contents, file names, sizes and sharing relationships on your device.
• Peer-to-peer sync keeps folders identical across your own devices without any server. Syncthing is the standard choice; it has no share links or web access.
• Web drives and file servers put a browser interface, share links and protocols such as WebDAV or SFTP on top of a disk or existing storage, usually without a full sync client. Cloudreve builds a cloud drive on local disk or object storage, Filestash fronts storage you already have, and copyparty turns a folder into a fast upload and download server.

Encryption: who can read your files

“Encrypted” means different things across this category, so read each project’s documentation.

• Server-side encryption (Nextcloud, ownCloud Classic, Pydio Cells, Cloudreve) encrypts files at rest with keys the server holds. It protects data stored with a third-party provider, but not against a compromised server or an administrator, and file names usually stay readable.
• Per-folder password encryption, as in Seafile’s encrypted libraries, keeps keys away from the server when you use the desktop client, but file names and sizes remain visible, and web access sends the password to the server.
• End-to-end encryption encrypts on the device before upload. Nextcloud offers it for selected folders; Peergos applies it to everything, metadata included.

All of these also rely on TLS for data in transit. If you self-host on a disk you control, full-disk encryption is often the simpler protection for data at rest.

What to check before you choose

1. Clients. Desktop sync for every operating system you use, files on demand, mobile apps with camera upload, and WebDAV for everything else. Cloudreve’s sync client needs its paid Pro edition, Sync-in relies on WebDAV for phones, and Syncthing’s official Android app has been discontinued.
2. Self-hosting effort. Nextcloud and ownCloud Classic need PHP, a database and a cache; Seafile and Pydio Cells need MariaDB or MySQL; Infinite Scale and OpenCloud store metadata on the filesystem and need no database, which makes backups a storage snapshot. Syncthing and copyparty need almost nothing.
3. Data layout. Sync-in and copyparty keep files as normal files on disk; other platforms use their own storage layouts or object storage, which matters for backups and later migrations.
4. Office editing. Most platforms connect to Collabora Online or OnlyOffice through the WOPI protocol rather than shipping their own editor.
5. Open source scope. Several projects have paid editions. Seafile Professional Edition is proprietary and holds full-text search and clustering; Pydio Cells keeps LDAP, SSO and MFA in paid editions; Filestash and Cloudreve sell commercial or Pro licenses; OpenCloud’s Helm charts need a subscription. Some official ownCloud Infinite Scale builds carry a non-commercial EULA even though the source is Apache 2.0.
6. Migration. Export from the service you are leaving (Google Takeout for Google Drive) and upload through a sync client or WebDAV.

Standards that help with portability

WebDAV, defined in RFC 4918, is the common file access protocol here: almost every platform listed exposes it, so file managers, backup tools and mobile apps can connect without a dedicated client. CalDAV and CardDAV do the same for calendars and contacts. For sharing between different servers, Open Cloud Mesh is a federation protocol now developed as IETF drafts; OpenCloud lists support for it, with CERNBox, ownCloud, Nextcloud and Seafile among the compatible platforms.

Projects not listed

File Browser was archived in 2026 and no longer receives security fixes. SFTPGo (AGPL, with a commercial Enterprise edition) is a file transfer server for SFTP, FTP and WebDAV rather than a sync-and-share platform. We did not find a notable source-available (non-OSI) project in this category; the closest cases are proprietary editions of open source products, described above.