I'm using PuTTY to ssh into a Debian machine. When I try to use Ctrl + [arrow key] to resize panes in tmux, the active pane just switches as if I was not holding Ctrl. Other Ctrl key shortcuts work fine. When I try the same thing using a different terminal, the shortcut works.

2 Answers 2


Add the following line to ~/.tmux.conf

set -g terminal-overrides "xterm*:kLFT5=\eOD:kRIT5=\eOC:kUP5=\eOA:kDN5=\eOB:smkx@:rmkx@"

Source: https://stuff.mit.edu/afs/athena/project/bsd/src/tmux-1.3/FAQ

Ctrl and arrow keys doesn't work in putty! What do I do?

putty inverts the sense of the cursor key mode on ctrl, which is a bit hard for tmux to detect properly. To get ctrl keys right, change the terminfo settings so kUP5 (Ctrl-Up etc) are the adjusted versions, and disable smkx/rmkx so tmux doesn't change the mode. For example with this line in .tmux.conf (assuming you have TERM set to xterm):

set -g terminal-overrides "xterm*:kLFT5=\eOD:kRIT5=\eOC:kUP5=\eOA:kDN5=\eOB:smkx@:rmkx@"

Note that this will only work in tmux 1.2 and above.

  • Doesnt work. How to make it work?
    – Kangarooo
    Jan 10, 2021 at 23:59

Ctrl+b then release both and then Ctrl+arrow key to adjust size(holding Ctrl press fast multiple times arrow if needed)

Make sure that you don't have a long pause between pressing, otherwise it will resize just one step at time

  • 1
    That's what I am doing and it doesn't work Jan 10, 2017 at 14:58
  • Pause between Ctrl+b and subsequent Ctrl+arrow key must be as short as possible, (I think it a second, no more). This bothered me too until I found that it need to be entered pretty fast
    – Alex
    Jan 10, 2017 at 15:36
  • 1
    Using Putty 0.69 on Windows and tmux 2.1 on Ubuntu 16.04, Ctrl + Arrow is just detected the same as arrow without Ctrl. Setting the terminal overrides as suggested in the other answer fixes things.
    – bobpaul
    Jun 20, 2017 at 17:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.