There are plenty of online tools that will test your bandwidth, but for those who cherish the elegance of the command line, here’s a great command to alias and put in your shell’s config.
For me that’s zsh, and here’s the alias:
alias bt=“wget http://cachefly.cachefly.net/400mb.test”
For those who don’t know, CacheFly is widely accepted as the premier CDN in the world. The beauty of this test is that no matter where you are you’re getting that 400MB file from the closest location to you. This means you’re testing your connection rather than random drama points between you and a given destination.
[ NOTE: There are also 100MB and 200MB versions as well. Just change the 400 to one of those in the URL. ]