TeraTerm Pro

TeraTerm is an open-source, VT100 and TEK4010 terminal emulator with select features from VT200 and VT300 series terminals. All versions support Telnet and serial ports, while some versions have added support for SSH.

Quote from the TeraTerm Pro web site:

"Tera Term (Pro) is a free software terminal emulator (communication program) for MS-Windows. It supports VT100 emulation, telnet connection, serial port connection, and so on."

Web Site

There are several versions of TeraTerm Pro available on the Internet.

  • An open source version of TeraTerm including support for SSH is available at https://ttssh2.sourceforge.jp/. This is the version that has been reviewed.
  • TeraTerm Pro Web 3.1.3 is available at https://www.ayera.com/teraterm/.
  • Other versions of TeraTerm which include support for SSH v1.5 are available. These have not been evaluated since any implementation of SSH should include support for SSH v2.


TeraTerm supports a variety of customizations allowing the display to be configured to the user's personal taste. This includes:

  • Screen size (number of rows and columns) including full-screen mode
  • Font selection and size
  • Background and font color for standard and bolded text

Other features supported include:

  • Output logging
  • Scroll-back buffer
  • Printer support
  • File transfer support
  • Supports ANSI color settings from the host


TeraTerm provides 3 basic communication protocols.

  • Telnet - standard Telnet protocol used for terminal communication with most systems. All data on the network is in plain-text which could be viewed by anyone with a network sniffer between the PC and the target server.
  • SSH - an encrypted implementation of communication similar to Telnet. All communication cannot be viewed while on the network. TeraTerm Pro includes support for:
    • Authentication methods
      • Keyboard-interactive - username and password verified by SYSUAF
      • Pageant - SSH key exchange
    • Tunneling including X11 forwarding
  • Serial - user specified COM port and communication parameters.

Additional communications options are available by editing the teraterm.ini file in the program directory. If the Telnet connection is going through a firewall that drops idle connections, a communication parameter may be set to send keepalive messages regularly to prevent the connection from being dropped.

File transfers may be done using one of 5 different protocols.

  • SCP - Secure Copy
  • Kermit
  • X-Modem
  • Z-Modem
  • B-Plus
  • Quick VAN

Keyboard Mapping

Due to the diferences between the DEC VT series keyboards and the standard, and some not-so-standard, PC keyboards, terminal emulators must choose how to map many of the function and editing keys. The default keyboard configuration for TeraTerm includes mapping of the editing keys based on key placement.

The 6 editing keys on the VT series keyboards are:

Find Insert Remove
Select Previous Next

These keys are mapped to standard PC keyboard for these keys is:

Insert Home Page Up
Delete End Page Down

Key mapping based on key placement maps the PC keys to the DEC VT keys as:

  • Insert -> Find
  • Home -> Insert
  • Page Up -> Remove
  • Delete -> Select
  • End -> Previous
  • Page Down -> Next

Function keys F1-F12 are mapped to the DEC VT function keys F1-F12. Shift F3 - shift F10 on the PC keyboard are mapped to the DEC VT function keys F13-F20.

By default, the backspace key is mapped to the backspace key and the PC delete key transmits the delete character. For compatibility with DEC VT terminals, both of these should be changed in the keyboard setup.

The keyboard mapping may be changed by editing the keyboard.cnf file in the program directory.


PARSEC Group works hard to maintain the accuracy and usefulness of its data. However, we cannot accept responsibility for the use or misuse of any information contained on this site. If you believe any information contained on this site is incorrect, please let us know through the use of our inquiry form.

Cookie Manager

We use cookies to enhance the features of our web site. We don't set optional cookies unless you enable them. Using this tool sets a cookie on your device to remember your preferences. For more detailed information about the cookies we use, see our Cookies page.

Necessary Cookies

Necessary cookies enable core functionality such as security, network management, and accessibility. You may disable these by changing your browser settings, but this may affect how the website functions.

Preference Cookies

Preference cookies enable this site to remember information that changes the way the website behaves or looks.

Statistics Cookies

Statistic cookies help us to understand how visitors interact with the site by collecting and reporting information anonymously.

Marketing Cookies

Marketing cookies are used to track visitors across websites. The intention is to display ads that are relevant and engaging for the individual user and thereby more valuable for publishers and third party advertisers.