Maestral

Maestral is an open-source Dropbox client written in Python. The project's main goal is to provide a client for platforms and file systems that are no longer directly supported by Dropbox.

Maestral currently does not support Dropbox Paper, the management of Dropbox teams, and the management of shared folder settings. If you need any of this functionality, please use the Dropbox website or the official client. Maestral does support syncing multiple Dropbox accounts and excluding local files from sync with a ".mignore" file.

The focus on "simple" file syncing does come with advantages: on macOS, the Maestral App bundle is significantly smaller than the official Dropbox app and uses less memory. The exact memory usage will depend on the size of your synced Dropbox folder and can be further reduced when running Maestral without a GUI.

Maestral uses the public Dropbox API which, unlike the official client, does not support transferring only those parts of a file which changed ("binary diff"). Maestral may therefore use more bandwidth that the official client. However, it will avoid uploading or downloading a file if it already exists with the same content locally or in the cloud.