PuTTY is described as 'Free and open-source terminal emulator supporting SSH, Telnet, and SCP. Portable, lightweight, and works offline to connect to remote systems securely' and is a leading terminal emulator in the os & utilities category. There are more than 100 alternatives to PuTTY for a variety of platforms, including Windows, Mac, Linux, Android and iPhone apps. The best PuTTY alternative is KiTTY, which is both free and Open Source. Other great apps like PuTTY are OpenSSH, MobaXterm, Tabby and Termux.