Sometimes, firefox will download the same file twice (or more) when I still have it. I do NOT want to turn off automatic downloading. I am asking, how to make firefox check if the file already exists before downloading. I understand that sometimes you willl download multiple files from a website, but, even though they are all called "image.jpg" they are all in fact different pictures. So, I think the solution to this is, when downloading a file, firefox should check if the file already exists. If it does exist, start the download for file(1) as usual, but ask the user "A file with this name already exists, are you sure you want to download it again ?" And the choices should be Yes (download continues) yes, and do not ask again for this filename (download continues) No (download is interrupted and partial file is deleted)