Starting with version 88.0 of the Firefox browser, FTP protocol has been disabled. This means that users won’t be able to access FTP servers directly from the Firefox browser after updating to version 88. If you try to access any FTP server using Firefox, it will display options to choose third-party FTP client applications. For this to work, you should have installed an FTP client such as FileZilla, WinSCP, Cyberduck or CuteFTP that associates itself as default app to handle FTP protocol on your PC.
Even though the aforementioned FTP clients are definitely much better at accessing FTP servers than a web browser, sometimes we need quick access to FTP servers for example to download files. So many of the Linux distros are available through FTP servers. We can download those files only of Firefox has FTP support enabled.
Update: The following method does not work with Firefox 91 and above. For Firefox 91 and above, you have to setup an external FTP app such as WinSCP to work with Firefox. You can also change FTP app for Firefox later.
Here is how we can re-enable FTP protocol support in Firefox:
- Launch Mozilla Firefox, enter about:config in the address bar and then click on Accept the risk to continue button.
- Search for a setting network.ftp.enabled and double-click on it to change its value to true.
- Now you have enabled FTP support in Firefox once again.
In order to check whether FTP support has been enabled, you can visit any public FTP servers such as ftp://ftp.vim.org or ftp://ftp.gnu.org. All of these servers these days also have an HTTP access site that gives you access to all the files through a simple HTML interface. There is no difference between the FTP and HTTP interfaces as far as downloading the files is concerned. But FTP protocol also allows for uploading of the files depending on the user account permissions and the server configuration.
The reason why Mozilla has decided to disable FTP support in Firefox 88.0 is because FTP is not an encrypted connection. They plan to completely remove FTP support in the future, so these instructions to enable FTP in Firefox may not work in the future versions.