Hi, I would think that it is not many people upload through Firefox and if do it is usually small files as it is slower than using a FTP Program such as : https://filezilla-project.org/. Also possibly taken out for security concerns. At this time I see no extensions that would work. To submit suggestions for new or changed features, may I suggest: Feedback: https://qsurvey.mozilla.com/s3/FirefoxInput/ or https://discourse.mozilla.org/c/add-ons Please let us know if this solved your issue or if need further assistance.