A little unknown ability in Filezilla FTP client is the fact you can use private keys to connect to remote servers without a password. While in the site manager where you add and remove sites to connect to there is no option to provide a private key, it is actually somewhere else.
Go to the menu bar along the top: Click edit and then settings. A settings popup box should appear now with a whole heap of different options to select, but we are going to be clicking “SFTP” – you should now see some text mentioning public key authentication. This is where we will load our key.
Click on the “Add keyfile” button and select your private key. You can add multiple private keys if you administer multiple servers each using different keys.
An Easier Way…
If you are a Windows user (presumably) and you have Putty, you can open up Pageant and add in your keys there as well and Filezilla will automatically be able to use them for connecting to servers as well.
If you don’t know what I am talking about and happy to add them in Filezilla, do that, but Pageant reduces the steps required and has the advantage of working with other applications that can use Pageant keys (like Sourcetree).
Hope this helps.