If you have a .zip file of an extension (often sourced from platforms like GitHub ), follow these steps to install it manually:

: Open Chrome and navigate to chrome://extensions/ .

: Reputable extensions like those from Sam Hoque claim 100% local processing, meaning they do not send your message data to external servers.

These extensions typically inject new interface elements, such as checkboxes or "Delete All" buttons, into the standard Facebook Messenger desktop site.

: Most updated versions (as of early 2026) are compatible with the latest Facebook UI and work across personal and business page inboxes. How to Install via ZIP (Manual Method)