Cyber security experts, network administrators using Nmap (“Network Mapper”) open source tool for network exploration and security auditing. If you want to scan your target with nmap tool without any additional installations, skills, or it is lazy to configure or open terminal and enter this commands then nmap.online for you.
nmap -F [hostname]
[hostname] is your host name or IP address
This command scan just the most popular 100 ports with the -F (fast scan) option.