How to base64 encode a string using the command line on macOS

echo -n 'blueballoons' | base64
=> Ymx1ZWJhbGxvb25z

The echo commands job is to output the string that is passed to it as an argument. By passing the -n flag we do not get the trailing newline in our output. Then we use the | to pipe the output to base64 which base64 encode the string, in this case “blueballoons”.