Screen goes with Ctrl+A. tmux on the other hand—as developed within screen—uses Ctrl+B. Both keystrokes, however, are also used in editors, shells, etc. Thus choosing either one degrades the user experience and functionality of those tools when used within tmux or screen.

What prefix conflicts the least with other programs' and shells' keybindings?

  • 6
    "which one conflicts least with other programs?" has nothing to do with opinion.
    – iconoclast
    Commented Nov 20, 2015 at 19:51
  • After changing ~/.tmux.conf don't forget to restart tmux server for changes to take effect (superuser.com/q/188491/105108).
    – ks1322
    Commented Jan 31, 2016 at 14:34
  • 1
    Alternative to using a prefix: Some terminals now offer tmux integration via "tmux -CC" (i.e. iTerm2 for macOS). That way tmux windows appear as tabs in the terminal. You could then use key bindings for managing tabs that don't conflict with any terminal program, i.e. by using the cmd key (aka super key, windows key).
    – cjay
    Commented Jan 30, 2019 at 22:09

22 Answers 22


I think ^\ (a.k.a. ^|) is the best if it's in a convenient position on your keyboard layout. Its uses in other programs are quite rare:

  • sending SIGQUIT to a process
  • aborting for or while loops in a shell when ^C is intercepted
  • toggle-input-method in emacs

I don't know of any other uses. Be careful to not accidentally kill a processes outside of tmux or screen after getting used to it. It happened to me only once in a few years though.


unbind-key C-b
set -g prefix 'C-\'
bind-key 'C-\' send-prefix


escape ^|^|
  • 3
    Just to let somebody else know, you should write 'C-\' instead of ` C-\ ` in the tmux config.
    – aignas
    Commented Feb 14, 2014 at 10:46
  • 3
    Don't forget to 'tmux source-file /path/to/tmux.conf' when finished to try out the new settings
    – user72923
    Commented May 23, 2014 at 15:16
  • 18
    but then I get in the habit of that command, and when I forget I'm in screen, I start accidentally sending SIGQUITs...
    – Kache
    Commented Apr 14, 2015 at 21:39
  • 3
    "if it's in a convenient position on your keyboard layout" by default it's not, are you implying that there is some popular remapping that you're using which makes C-\ convenient?
    – storypixel
    Commented Jan 17, 2017 at 16:06
  • 5
    'C-\' is a terrible prefix key, as building muscle memory around it will cause you to inadvertently send SIGQUIT when you're using tmux's that aren't configured this way. If we're going to shadow a process control key combination, then C-z is a much more benign option.
    – aparkerlue
    Commented Aug 31, 2018 at 17:58

For people who want to use backtick as the escape in tmux, you'll want to add:

unbind C-b
set -g prefix `
bind-key ` send-prefix

That last one is important, else you can't type a backtick for other purposes :-)

  • Backtick seems like a good idea until you paste in some SQL...
    – Synchro
    Commented Jan 9, 2013 at 9:43
  • 5
    @Synchro on tmux 1.8 it's not an issue anymore thanks to assume-paste-time option which is on by default (set to 1ms). See here: sourceforge.net/p/tmux/tmux-code/ci/…
    – ku1ik
    Commented Mar 27, 2013 at 20:46
  • I found this question looking for alternatives to backtick as it started to cause trouble after I got used to using backticks instead of $() in shells. Also it becomes a pain once you start writing a lot of Markdown. I've been using it for several years, but unfortunately I'll have to change it now.
    – kirelagin
    Commented Jul 1, 2014 at 20:09
  • 4
    In .tmux.conf I also have bind-key C-a set-option -g prefix C-a. Whenever I need to use backticks I hit `-Ctrl-a which sets my prefix to C-a. And I have bind-key C-b set-option -g prefix ` so I can hit C-a-C-b to go back
    – user383438
    Commented Dec 24, 2014 at 23:14
  • 1
    instead of using ` in bash, you should try to use the more modern and more readable alternative: $( and )
    – iconoclast
    Commented Nov 20, 2015 at 19:54

Ctrl+A is also known to cause problems with Emacs, including Bash in Emacs mode. It sounds like this is not a problem for you.

Ctrl+O is the other option I've seen. Apparently, this is the default in RatPoison (this is an X window manager that doesn't need a mouse). I've used Ctrl+O when using nested screens: Ctrl+O for the outer one and Ctrl+A for the inner ones. Worked well, but kinda scared my colleagues. :-)

I was just thinking and if you use vi rather than Emacs, there are a few alternatives. Ctrl+G isn't used by much, for instance.

  • 9
    For Emacs users Ctrl+O seems to be the the best pick: In emacs it´s only "open a new line at the cursor" and in bash "repeate a command sequence".
    – Flow
    Commented Nov 24, 2009 at 8:15
  • 2
    +1 if you are OK with right handed ctrl-operations, this looks like a good backup. I'm a lefty myself ;-) Commented Nov 24, 2009 at 16:56
  • 13
    I think Ctrl+O breaks vim
    – Mu Qiao
    Commented Mar 26, 2014 at 14:36
  • 15
    I agree with @MuQiao. Ctrl-o is used in Vim to jump to an older cursor position (equivalent of back button in many IDEs), a feature I use very often while browsing code in Vim. Ctrl-b is synonymous to PageUp in Vim. I don't use Ctrl-b at all on Vim. So for Vim users like me, Ctrl-b is still a better choice than Ctrl-o. I use C-j as my prefix key since C-j is synonymous to j or <Down> in Vim and nobody uses C-j to move one line down in Vim. I have this in my ~/.tmux.conf: set -g prefix2 C-j; bind-key C-j send-prefix -2
    – Susam Pal
    Commented Apr 10, 2014 at 9:44
  • C-j conflicts with CtrlP. Moving up and down the buffer list uses C-k and C-j respectively
    – blockloop
    Commented May 31, 2017 at 14:08

I've got CAPS-LOCK globally mapped to ESC. Then, I use M-Space (ie. CAPS-LOCK+ Space) for my prefix.

  • 1
    I'm trying to do this but if I hold CAPS-LOCK (thinking about my next command or something) tmux—or iTerm, not sure what's causing this—receives the ESC command repeatedly causing M-Space to then not work. Is there a way to disable that repeating key issue? For instance, it works when I quickly press CAPS-LOCK + Space, but not if I hold down CAPS-LOCK for a second or so and then press Space it doesn't register the M-Space chord...
    – sleighty
    Commented Apr 2, 2019 at 17:37
  • @sleighty you can have CAPS-LOCK mapped to ESC when pressed and released and CTRL when you hold down. C-Space then works nicely as tmux prefix, but just in general it's also great.
    – cviejo
    Commented Jun 2, 2022 at 7:50
  • @cviejo, how do you do this mapping based on how long you press? Commented Jun 27, 2022 at 15:32
  • Such a good one! I changed caps lock to ctrl on a system level. Now C-SPACE is prefix in tmux and <SPACE> leader in vim. Commented Jul 18, 2023 at 23:10

I use Ctrl-Q in tmux and it has worked well so far. I have to mention, though, that it conflicts with shell flow control. By default, Ctrl-Q is used to re-enable output after stopping it with Ctrl-S. Having been surprised by a stuck shell a few times after accidentally hitting Ctrl-S, I have learned not to press Ctrl-S.

(One could also turn off flow control altogether with stty -ixon, or bind different keys to stty start and stty stop.)

# tmux.conf
unbind C-b
set -g prefix C-q
  • I've adopted this bind and I find it very convenient. Thanks! Commented Aug 23, 2013 at 7:29
  • My favorite as well, since I always disable the terminal control flow stuff. Commented Aug 24, 2013 at 3:10
  • 2
    Used in emacs for quote-inserted. Sample use (in emacs): if I want to search for the next tab character - <Ctrl-s>+<Ctrl-q>+<TAB>
    – nhed
    Commented Apr 8, 2014 at 17:15
  • Ctrl-Q is great, hitting it twice to re-enable output is not too bad.
    – doak
    Commented Jun 5, 2020 at 16:13

I use a complex system for screen. My default escape is set to \140\140, which is backtick. The Ctrl-A complicates both Emacs and command line editing for me within Zsh, and I dislike Ctrl-O (2 hand operations for most screen actions).

I rebind 's' to screen 1 so that new sessions are created from left to right on the keyboard starting at 1. This allows me to reserve screen 0 for what I consider persistent or reference windows. It's very quick one handed gesture to (backtick)1, (backtick)2, (backtick)3 to swap between windows.

The issue with using backtick in a Unix environment is when attempting to cut-and-paste shell/Perl script code. For this reason I bindkey F11/F12 to switch between my escape character.

bindkey -d -k F1        escape ^O^O # bound to F11
bindkey -d -k F2        escape \140\140 # bound to F12

This will swap the escape to Ctrl-O for when I'm doing cut-and-paste operations. I've found hitting a double tick is simple, and a good trade off for most screen operations.

Revisiting this answer with a newer solution that allows for toggling the mode by hitting F12, and using a caption to indicate mode.

## command characters
escape \140\140                # default is `

## sets caption and escape toggle
bindkey -d -k F2 process a     # bound to F12

## initial caption
caption always '%{= kW}%?%F%{+b KW}%:%{= kK}%? %= %?%F%{-b .c}>>>%{-}%? | %-w%{mW}%n* %t%? @%u%?%{-}%+w '

## registers to toggle bindkeys
register a "\140:eval 'bindkey -d -k F2 process b' 'process c' 'escape \\017\\017'^M"
register b "\017:eval 'bindkey -d -k F2 process a' 'process d' 'escape \\140\\140'^M"

## registers to change captions
register c "\140:caption string '%{= kW}%?%F%{+b mW}%:%{= kK}%? %= %?%F%{.c}ALT%{-}%? | %-w%{KW}%n* %t%? @%u%?%{-}%+w '^M"
register d "\017:caption string '%{= kW}%?%F%{+b KW}%:%{= kK}%? %= %?%F%{.c}>>>%{-}%? | %-w%{mW}%n* %t%? @%u%?%{-}%+w '^M"
  • Creative solution. I'm impressed.
    – staticsan
    Commented Nov 25, 2009 at 2:30
  • bind-key -n F11 set -g prefix ` bind-key -n F12 set -g prefix C-o Updates for tmux in case others want to adapt this. Commented Feb 10, 2012 at 4:49
  • 1
    Is there a way to set some kind of minimal timeout for prefix+other_key combo in tmux so when pasting code it doesn't trigger any command but when typing backtick+key from keyboard it does because the pause between backtick and the other key was longer?
    – ku1ik
    Commented May 5, 2012 at 16:15
  • What about Ctrl-`? This can be bound (for my setup) by C-@ (found out with cat -v).
    – doak
    Commented Jun 5, 2020 at 16:23

I like to reserve ^Space for very special/common operations because I find it to be the easiest prefix to type, but right now I'm trying it mapped as the prefix in tmux.

It leaves your fingers free to instantly jump to the command you want to type. Give it a try.

  • 4
    That didn't last long – I'm back to ^j. ^Space is too similar to commands that I use to invoke OSX-level apps (Spotlight, QuickSilver, DTerm).
    – terrace
    Commented Aug 22, 2010 at 3:32
  • I use C-j too. This is what I use in my ~/.tmux.conf: set -g prefix2 C-j; bind-key C-j send-prefix -2
    – Susam Pal
    Commented Apr 10, 2014 at 9:46
  • 1
    I also use C-Space, it is not used almost anywhere else.
    – Mahdi
    Commented Jun 1, 2016 at 7:44
  • 1
    C-space is perfect for me, as I'm on a Chromebook :D Commented Nov 30, 2016 at 17:39

A belated suggestion: ctrl-s. ctrl-s has a number of advantages:

  1. On the home row.
  2. Still close to ctrl-a (in fact, for most typers it will use the same two fingers they used for ctrl-a), so the muscle memory switch from ctrl-a to ctrl-s is trivial -- for me, it became second nature within about an hour of first trying it.
  3. Frees up ctrl-a for emacs-style "back to beginning of line" or vim-style "increment number" operations. Or hey, for running screen inside a tmux pane without needing to worry about escaping prefix characters to control the embedded screen instance. (I often do this using a local tmux with panes containing ssh sessions to remote servers, in which I run screen)
  4. Doesn't override or add escaping-requirements to any other commonly-used terminal functionality. nothing the vast majority of people use today is on ctrl-s!

Of course, the reason that nothing is on ctrl-s is that in the terminal, it traditionally is used for flow control, dating back to the days before paging tools like more and less were common. I'm sure some GUI terminal program somewhere still has that flow-control functionality enabled by default, but I haven't actually bumped into one; the gui terminal programs I've tried all seem to completely ignore it by default, which makes that convenient key combination available for more productive uses.

So if you're not actually using screen/tmux from within (for example) a raw Linux terminal, but rather from a GUI-based terminal, then I recommend giving ctrl-s a try; it's made zipping about in tmux and screen a lot more convenient for me.

  • 5
    Ctrl-s is forward search, for when I go to far with Ctrl-r :) Commented Aug 24, 2013 at 3:12
  • Ctrl-S is common for stopping console output (aka "freezing" it). This bit me when I tried remapping it.
    – Dave
    Commented Sep 23, 2016 at 20:00

A key without conflict may be C-z, as it is usually used to send the program to the background to continue another thing on the shell that started it. I don't do this when I have tmux.

  • The only problem I've had with using C-z is that most other people are using C-b, so my muscle memory is off when pair programming on someone else's machine.I end up having to run fg a lot after erroneously typing C-z. Commented Jul 24, 2016 at 19:37
  • The great think about C-z is that, assuming you don't want to use C-a, it's very close to the left Ctrl key, which is the only control key on most notebook computer keyboards these days. Also close to the Caps Lock if you have that mapped to Ctrl. I map my Caps Lock to Esc since I'm often using a Kinesis Freestyle Solo keyboard that has the Esc key in an awkward place. Commented Jul 24, 2016 at 19:42

I've heard of ` (backtick) being used and then you just have to type it twice for an actual backtick. Might be better for vi users who are used to the action (unless you do the Caps lock thing).

  • How can you define backtick for tmux? Commented Feb 8, 2011 at 21:16
  • Something like: unbind C-b; set -g prefix ''; bind '' send-prefix; see Darren Hall's answer above.
    – jmhmccr
    Commented Feb 10, 2011 at 0:55
  • I'm with backtick for about a year and I'll never go back to two-key/combo prefix. Give it a try.
    – ku1ik
    Commented Jan 15, 2013 at 15:29

I recommend C-j, which doesn't interfere much with vi or emacs. Essentially, I agree with a comment by Susam Pal, which seems worthy of showing up as an answer, since the others all seem to have significant conflicts from my perspective.

I use C-j as my prefix key since C-j is synonymous to j or in Vim and nobody uses C-j to move one line down in Vim. I have this in my ~/.tmux.conf:

set -g prefix2 C-j; bind-key C-j send-prefix -2

  • 1
    Based on your recommendation, I have been using C-j for a while and the only conflict I've found is with the CtrlP vim plugin. C-j and C-k are used to move down and up the options, respectively.
    – blockloop
    Commented May 26, 2017 at 23:59
  • 1
    There are a lot more in the Vim-world, like moveing windows around etc. I you are a Vim user, I would avoid remapping your cursor keys.
    – doak
    Commented Jun 5, 2020 at 16:17

For Programmer Dvorak keyboard layout, it is pretty neat to use a minus (dash) key as a prefix, i.e. ctrl+-.
The minus key is on single quote key position in qwerty layout. Also I've caps lock key function as a ctrl key. Following is a tmux conf, to set it as a prefix:

unbind C-b
set -g prefix C-_
bind C-_ send-prefix
bind - last-window

You may wonder, why the underscore is used instead of minus? Refer to Tmux: how do I bind to C— (control-minus)?
For qwerty, you might apply How do I bind the tmux prefix key to C-'? solution, in order to retain same shortcut.

I would say this is a perfect prefix if you use Vim/Neovim. Because prefixes, such as ctrl+a or ctrl+b, do shadow (overlap) Vim's functionality, in either way.


I am using Alt+F. I just added it, and it has been much better than C-a or C-b. M-f doesn't require any move from my home position (since alt is already below my thumbs) and it doesn't force my pinkie finger.

unbind C-b
set-option -g prefix M-f
  • Ergonomically, this would have been a good option, but Alt + F moves forward a word in Bash
    – r_31415
    Commented Mar 6, 2022 at 6:50
  • I use vi mode on bash/zsh, so I never used this.
    – Jhon
    Commented Mar 13, 2022 at 11:28

Personally, b is just too far away from Ctrl for me. When I use tmux, I alway change the binding from C-b to C-a. The main conflict with C-a is select all, but I have not found this to be a problem with the programs I use tmux with.

  • indeed, i use the default (in screen, never tried tmux) and haven't yet found a need to change it. Commented Nov 24, 2009 at 4:31

As a GNU emacs, zsh, and MS Windows user, I use Control-T. (e.g. in .screenrc:)

escape "^T^T"

Yes Control-T has something bound to it, like the pull down menu in Ubuntu's aptitude, or transpose character in Emacs.

I disregarded C-o because it requires two hands for me.


I think the best solution is ^C. Emacs uses ^C as a prefix key, and I find that when I need to type ^C in a shell I almost always type two anyway. :-)

unbind-key C-b
set -g prefix C-c
bind-key C-c send-prefix

I use Caps Lock, and on OSX you need to do some special stuff to get it to work.



You can use backtick. Some older versions of tmux do not support backtick, so you can do the following to workaround (that would add C-`, C-@ and C-space as your meta at the same time though):

# meta prefix - @ - backtick
unbind C-b
set -g prefix C-@
bind C-@ send-prefix
bind C-@ last-window

I normally remap my CapsLock to Ctrl, so it makes even more sense with the backtick.

  • I use this as well. C-Space is quite easy to type.
    – kzh
    Commented Aug 21, 2014 at 16:56
  • The backtick is pretty good. However its not terminal friendly as it turns out. You definitely cannot go wrong with xterm on linux, but terminals like putty and iTerm2 (macos) have issues emulating it properly. Luckily in iTerm2 you can workaround it in the configuration. I don't use windows/putty a lot, so ctrl-space seems to be a feasible workaround. :)
    – Alex
    Commented Aug 23, 2014 at 19:02

Most Answers here use Ctrl as part of a key combination.
When I used Ctrl, my pinkie finger started to hurt because I always had to spread it down to Ctrl.
I use Alt-j which I type with my left thumb and my right index finger and it's very convenient. I also haven't found any collisions with any other program so far.

unbind C-b
set-option -g prefix M-j

For GNU screen, mapping the backtick to escape, the following in ~/.screenrc works for me.

escape ``

I like the suggestion of binding ctrl-\ as the prefix, but in order to get this to work on Linux Mint 12, I had to escape the place the binding at the bottom. Otherwise, it wouldn't take. See my .tmux.conf here: Using tmux with both emacs and vim

  • Please don't refer to answers as "above" and "below" as the order could change. Link the answer instead. Thanks for your answer :)
    – Flow
    Commented Feb 4, 2012 at 9:43

I think that Mac users will find the § more convenient than the backtick.

On non-Mac keyboard, the backtick is positioned at about the same key as the § on Mac keyboards. So, to experience the same convenience as the people who suggest to use the backtick, use the paragraph-sign on a Mac keyboard.

Using the backtick on Mac keyboards is tricky as it is located very near to the left (⇧)shift, (⌃)control, and (⌥)alt-keys. On MacBooks even near the left fn-key.

  • Define Mac keyboard ;-)
    – Arjan
    Commented Jul 1, 2016 at 13:15
  • Okay, you've a point here, I meant a Apple Mac US keyboard layout, though regardless a full extended or a macbook keyboard.
    – nanitous
    Commented Jul 10, 2016 at 15:54

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