# httprobe > Take a list of domains and probe for working HTTP and HTTPS servers. > More information: . - Probe a list of domains from a text file: `cat {{input_file}} | httprobe` - Only check for HTTP if HTTPS is not working: `cat {{input_file}} | httprobe --prefer-https` - Probe additional ports with a given protocol: `cat {{input_file}} | httprobe -p {{https:2222}}` - Display help: `httprobe --help`