Syncthing

Syncthing is an open-source continuous file synchronization tool for keeping folders in sync across trusted devices. Key features include:

• No central cloud server storing your files
• Real-time sync between two or more computers
• Encrypted communication with authenticated device identities
• Open protocol and open-source code
• Works across desktop, server, and many Unix-like platforms

Use Syncthing when you want ongoing sync between your own machines or trusted devices. For quick nearby transfers, use LocalSend. For temporary remote sharing links, use Wormhole or OnionShare.