Since Firefox can no longer handle ftp:// links natively, experts recommend these robust, free, and open-source alternatives: FileZilla - The free FTP solution
However, Mozilla officially in Firefox 90 (July 2021) due to the protocol's inherent security risks, such as transmitting data in unencrypted cleartext. Users looking for a "Mozilla FTP client" must now use dedicated external software. The Best FTP Client Alternatives in 2026 mozilla ftp client download