Install the Telnet Client in Windows 10

What is Telnet?

Telnet is a small tool that opens a plain text connection to another computer. Today people mostly use it to test a port. A port is like a numbered door on a server. Each service, such as a website or email, uses its own door. Telnet tells you if the door is open. Windows 10 has Telnet built in, but it is switched off.

Method 1: Windows Features

1. Click Start and type Turn Windows features on or off.
2. Open the result.
3. Scroll down the list.
4. Tick the box beside Telnet Client.

   

5. Click OK.
6. Wait while Windows installs it.
7. Click Close.

Method 2: Command line

1. Click Start and type cmd.
2. Right-click Command Prompt and choose Run as administrator.
3. Type this and press Enter:

   dism /online /Enable-Feature /FeatureName:TelnetClient

   This command turns on the Telnet Client feature.
4. Wait for "The operation completed successfully."

Test a port

1. Open a normal Command Prompt.
2. Type telnet, then a space, the server name or IP, a space, and the port number. Example:

   telnet example.com 80

   This tries to open port 80 (the web door) on example.com.
3. If the screen turns blank or shows some text, the port is open.
4. If you see "Could not open connection to the host", the port is closed, blocked, or the server is down.
5. To quit, press Ctrl + ], then type quit and press Enter.

Common ports to test

Quick recap

• Telnet is built into Windows 10 but turned off.

  

• Turn it on in Turn Windows features on or off.
• Run telnet host port to test a port.
• Do not use Telnet for passwords.