Check if port is accessible from a PC

Port:

If the usual telnet www.google.com 443 isn't an option, you can run this command via PowerShell:

tnc www.google.com -port 443

And if it needs to be run from the Command Prompt, it can be invoked like this (PowerShell 4+):

PowerShell -Command "tnc www.google.com -port 443"

And for earlier PowerShell versions:

PowerShell -Command "(new-object Net.Sockets.TcpClient).Connect('www.google.com', 443)"

URL:

Test the connection to a URL:

PowerShell -Command "Invoke-WebRequest -UseBasicParsing -Uri 'https://www.google.com.au/'"