cURL and Wget are popular web interface command line utilities that among their many features can resume interrupted or canceled downloads. cURL is a library with a command-line frontend, while Wget is a command line tool.
Daniel Stenberg’s cURL has a permissive license that has perhaps led it to become very widespread, installed “from the factory” in operating systems from Windows, MacOS, Linux to automobiles and many other embedded systems. cURL’s man page is perhaps best used by text search.
curl -O -C - https://mysite.example
--continue-at -continue a previous transfer, automatically determining byte offset.
wget -C htttps://mysite.example