The Zotero Connector for Safari is currently unavailable for download, and existing installations will stop working if you upgrade to Safari 13. Existing installations will continue to work in Safari 12.

We're currently evaluating our options for best supporting Safari users going forward. Follow @zotero on Twitter for updates.

In the meantime, you can use either the Zotero Connector for Firefox or Chrome or the Zotero Bookmarklet in Safari.

In Safari 13, Apple is discontinuing support for the original type of Safari extension, which affects the Zotero Connector and many other extensions.

These Safari extensions, which work similarly to extensions for Chrome and Firefox, are being phased out in favor of Safari App Extensions, a much more limited type of extension that must be distributed as part of a Mac app. Legacy Safari extensions will no longer work in Safari 13.

For the best Zotero experience, you may wish to use the Zotero Connector for Chrome or Firefox instead. Firefox and Chrome provide powerful extension frameworks that allow us to offer advanced functionality such as automatic proxy detection and automatic RIS/BibTeX import, features that weren't possible in Safari even before Apple further restricted what Safari extensions can do. We're also able to release updates to the Chrome and Firefox extensions immediately, rather than waiting for updates to be approved by Apple.

Regardless of future Safari extension support, you'll still have the option of saving to your Zotero library using the Zotero Bookmarklet in Safari.

See this forum thread for further discussion of this issue.