PuTTY is a free implementation of Telnet and SSH for Windows and Unix platforms, along with an xterm terminal emulator. PuTTY is a client program for the SSH, Telnet and Rlogin network protocols.

These protocols are all used to run a remote session on a computer, over a network. PuTTY implements the client end of that session: the end at which the session is displayed, rather than the end at which it runs.

In really simple terms: you run PuTTY on a Windows machine, and tell it to connect to (for example) a Unix machine. PuTTY opens a window. Then, anything you type into that window is sent straight to the Unix machine, and everything the Unix machine sends back is displayed in the window. So you can work on the Unix machine as if you were sitting at its console, while actually sitting somewhere else.

Can I copy and paste text between PuTTY and other Windows applications?

Yes. When you select text in the PuTTY window it automatically copies the text to the clipboard, without the need of pressing Ctrl-C or anything else. To paste the clipboard contents into a PuTTY window, you just need to click the right mouse button.

Does PuTTY work on macOS?

No. PuTTY is only available for Windows and Unix-based OS. As of version 0.68, PuTTY executables run on versions of Windows from XP onwards, up to and including Windows 11. If you need a macOS remote login with the SSH protocol, OpenSSH works with macOS and Linux, it is also free and open source.

What's a good alternative to PuTTY?

KiTTY is a fork of the original PuTTY client. It's based on PuTTY architecture and adds many new features for a Windows terminal app.

What's New

  • Windows installer scope is back to the normal 'per machine' setting, reverting 0.78's security workaround.

Note: this means that installing the 0.79 or later Windows installer will not automatically uninstall 0.78, if 0.78 was installed using its default 'per user' scope. In that situation we recommend uninstalling 0.78 first, if possible. If both end up installed, uninstalling both and then re-installing the new version will fix things up.

  • Terminal mouse tracking: support for mouse movements which are not drags.
  • Terminal mouse tracking: support for horizontal scroll events (e.g. generated by trackpads).
  • Backwards compatibility fix: certificate-based user authentication now works with OpenSSH 7.7 and earlier.
  • Bug fix: in a session using the 'Raw' protocol, pressing ^D twice in the terminal window could cause an assertion failure.
  • Bug fix: terminal output could hang if a resize control sequence was sent by the server (and was not disabled in the Features panel) but PuTTY's window was set to non-resizable in the Window panel.
  • Bug fix: GTK PuTTY could fail an assertion if a resize control sequence was sent by the server while the window was docked to one half of the screen in KDE.
  • Bug fix: GTK PuTTY could fail an assertion if you tried to change the font size while the window was maximised.
  • Bug fix: the 'bell overload' timing settings were misinterpreted by Unix PuTTY and pterm 0.77/0.78; if any settings were saved using these versions, confusion can persist with newer versions.
  • Bug fix: SSH authentication banners were not reliably printed if a server sent one immediately before closing the connection (e.g. intended as a user-visible explanation for the connection closure).
  • Bug fix: the 'close' command in PSFTP always reported failure, so that ending a psftp -b batch script with it would cause PSFTP as a whole to believe it had failed, even if everything worked fine.
  • Bug fix: certificate handling would do the wrong thing, for RSA keys only, if you specified a detached certificate to go with a PPK file that had a different certificate embedded.
  • Bug fix: Windows Pageant's option to write out a configuration file fragment for Windows OpenSSH now works even if you have a space in your user name.
  • Bug fix: in local-line-editing mode, pressing ^U now just clears the line, instead of clearing it and then inserting a literal ^U.
  • Several bug fixes in edge cases of terminal wrapping, involving double-width characters.

Legal Warning: Use of PuTTY, PSCP, PSFTP and Plink is illegal in countries where encryption is outlawed. I believe it is legal to use PuTTY, PSCP, PSFTP and Plink in England and Wales and in many other countries, but I am not a lawyer and so if in doubt you should seek legal advice before downloading it. You may find this site useful (it's a survey of cryptography laws in many countries) but I can't vouch for its correctness.

Use of the Telnet-only binary (PuTTYtel) is unrestricted by any cryptography laws.