i3 User’s Guide =============== Michael Stapelberg March 2010 This document contains all information you need to configuring and using the i3 window manager. If it does not, please contact me on IRC, Jabber or E-Mail and I’ll help you out. For a complete listing of the default keybindings, please see the manpage. == Using i3 === Creating terminals and moving around A very basic operation is to create a new terminal. By default, the keybinding for that is Mod1+Enter, that is Alt+Enter in the default configuration. By pressing Mod1+Enter, a new terminal will be created and it will fill the whole space which is available on your screen. image:single_terminal.png[Single terminal] It is important to keep in mind that i3 uses a table to manage your windows. At the moment, you have exactly one column and one row which leaves you with one cell. In this cell, there is a container in which your newly opened terminal is. If you now open another terminal, you still have only one cell. However, the container has both of your terminals. So, a container is just a group of clients with a specific layout. You can resize containers as they directly resemble columns/rows of the layout table. image:two_terminals.png[Two terminals] To move the focus between the two terminals, you use the direction keys which you may know from the editor +vi+. However, in i3, your homerow is used for these keys (in +vi+, the keys are shifted to the left by one for compatibility with most keyboard layouts). Therefore, +Mod1+J+ is left, +Mod1+K+ is down, +Mod1+L+ is up and `Mod1+;` is right. So, to switch between the terminals, use +Mod1+K+ or +Mod1+L+. To create a new row/column, you can simply move a terminal (or any other window) to the direction you want to expand your table. So, let’s expand the table to the right by pressing `Mod1+Shift+;`. image:two_columns.png[Two columns] === Changing mode of containers A container can be in different modes: default:: Windows are sized so that every window gets an equal amount of space of the container. stacking:: Only the focused client of the container is displayed and you get a list of windows at the top of the container. tabbed:: The same principle as +stacking+, but the list of windows at the top is only a single line which will be vertically split. To switch the mode, press +Mod1+e+ for default, +Mod1+h+ for stacking and +Mod1+w+ for tabbed. image:modes.png[Container modes] === Toggling fullscreen mode for a window To display a window fullscreen or to go out of fullscreen mode again, press +Mod1+f+. === Opening other applications Aside from opening applicatios from a terminal, you can also use the handy +dmenu+ which is opened by pressing +Mod1+v+ by default. Just type the name (or a part of it) of the application which you want to open. It has to be in your +$PATH+ for that to work. Furthermore, if you have applications you open very frequently, you can also create a keybinding for it. See the section "Configuring i3" for details. === Closing windows If an application does not provide a mechanism to close (most applications provide a menu, the escape key or a shortcut like +Control+W+ to close), you can press +Mod1+Shift+q+ to kill a window. For applications which support the WM_DELETE protocol, this will correctly close the application (saving any modifications or doing other cleanup). If the application doesn’t support it, your X server will kill the window and the behaviour depends on the application. === Using workspaces Workspaces are an easy way to group a set of windows. By default, you are on the first workspace, as the bar on the bottom left indicates. To switch to another workspace, press +Mod1+num+ where +num+ is the number of the workspace you want to use. If the workspace does not exist yet, it will be created. A common paradigm is to put the web browser on one workspace, communication applications (+mutt+, +irssi+, ...) on another one and the ones with which you work on the third one. Of course, there is no need to follow this approach. If you have multiple screens, a workspace will be created on each screen. If you open a new workspace, it will be bound to the screen you created it on. When you switch to a workspace on another screen, i3 will set focus to this screen. === Moving windows to workspaces To move a window to another workspace, simply press +Mod1+Shift+num+ where +num+ is (like when switching workspaces) the number of the target workspace. Similarly to switching workspaces, the target workspace will be created if it does not yet exist. === Resizing columns/rows To resize columns or rows just grab the border between the two columns/rows and move it to the wanted size. Please keep in mind that each cell of the table holds a +container+ and thus you cannot horizontally resize single windows. See <> for how to configure i3 to be able to resize columns/rows with your keyboard. === Restarting i3 inplace To restart i3 inplace (and thus get it into a clean state if it has a bug, to reload your configuration or even to upgrade to a newer version of i3) you can use +Mod1+Shift+r+. Be aware, though, that this kills your current layout and all the windows you have opened will be put in a default container in only one cell. Saving the layout will be implemented in a later version. === Exiting i3 To cleanly exit i3 without killing your X server, you can use +Mod1+Shift+e+. === Snapping Snapping is a mechanism to increase/decrease the colspan/rowspan of a container. Colspan/rowspan is the amount of columns/rows a specific cell of the table consumes. This is easier explained by giving an example, so take the following layout: image:snapping.png[Snapping example] To use the full size of your screen, you can now snap container 3 downwards by pressing +Mod1+Control+k+ (or snap container 2 rightwards). === Floating Floating is the opposite of tiling mode. The position and size of a window are then not managed by i3, but by you. Using this mode violates the tiling paradigm but can be useful for some corner cases like "Save as" dialog windows or toolbar windows (GIMP or similar). You can enable floating for a window by pressing +Mod1+Shift+Space+. By dragging the window’s titlebar with your mouse, you can move the window around. By grabbing the borders and moving them you can resize the window. Bindings for doing this with your keyboard will follow. Floating clients are always on top of tiling clients. == Configuring i3 This is where the real fun begins ;-). Most things are very dependant on your ideal working environment, so we can’t make reasonable defaults for them. While not using a programming language for the configuration, i3 stays quite flexible regarding to the things you usually want your window manager to do. For example, you can configure bindings to jump to specific windows, you can set specific applications to start on a specific workspace, you can automatically start applications, you can change the colors of i3 or bind your keys to do useful stuff. To change the configuration of i3, copy +/etc/i3/config+ to +~/.i3/config+ and edit it with a text editor. === General configuration font:: Specifies the default font you want i3 to use. Use an X core font descriptor here, like +-misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1+. You can use +xfontsel(1)+ to pick one. === Keyboard bindings A keyboard binding makes i3 execute a command (see below) upon pressing a specific key. i3 allows you to bind either on keycodes or on keysyms (you can also mix your bindings, though i3 will not protect you from overlapping ones). * A keysym (key symbol) is a description for a specific symbol, like "a" or "b", but also more strange ones like "underscore" instead of "_". These are the ones you also use in Xmodmap to remap your keys. To get the current mapping of your keys, use +xmodmap -pke+. * Keycodes however do not need to have a symbol assigned (handy for some hotkeys on some notebooks) and they will not change their meaning as you switch to a different keyboard layout. My recommendation is: If you often switch keyboard layouts because you try to learn a different one, but you want to keep your bindings at the same place, use keycodes. If you don’t switch layouts and like a clean and simple config file, use keysyms. *Syntax*: ---------------------------------- bindsym [Modifiers+]keysym command bind [Modifiers+]keycode command ---------------------------------- *Examples*: -------------------------------- # Fullscreen bind Mod1+f f # Restart bind Mod1+Shift+r restart # Notebook-specific hotkeys bind 214 exec /home/michael/toggle_beamer.sh -------------------------------- Available Modifiers: Mod1-Mod5, Shift, Control:: Standard modifiers, see +xmodmap(1)+ Mode_switch:: Unlike other window managers, i3 can use Mode_switch as a modifier. This allows you to remap capslock (for example) to Mode_switch and use it for both: typing umlauts or special characters 'and' having some comfortably reachable key bindings. For example, when typing, capslock+1 or capslock+2 for switching workspaces is totally convenient. Try it :-). === The floating modifier To move floating windows with your mouse, you can either grab their titlebar or configure the so called floating modifier which you can then press and click anywhere in the window itself. The most common setup is to configure it as the same one you use for managing windows (Mod1 for example). Afterwards, you can press Mod1, click into a window using your left mouse button and drag it to the position you want it at. *Syntax*: -------------------------------- floating_modifier -------------------------------- *Examples*: -------------------------------- floating_modifier Mod1 -------------------------------- === Layout mode for new containers This option is only available when using the new lexer/parser (pass +-l+ to i3 when starting). It determines in which mode new containers will start. See also <>. *Syntax*: --------------------------------------------- new_container new_container stack-limit --------------------------------------------- *Examples*: --------------------- new_container tabbed --------------------- === Border style for new windows This option is only available when using the new lexer/parser (pass +-l+ to i3 when starting). It determines which border new windows will have. *Syntax*: --------------------------------------------- new_window --------------------------------------------- *Examples*: --------------------- new_window bp --------------------- === Variables As you learned in the previous section about keyboard bindings, you will have to configure lots of bindings containing modifier keys. If you want to save yourself some typing and have the possibility to change the modifier you want to use later, variables can be handy. *Syntax*: -------------- set name value -------------- *Examples*: ------------------------ set $m Mod1 bindsym $m+Shift+r restart ------------------------ Variables are directly replaced in the file when parsing, there is no fancy handling and there are absolutely no plans to change this. If you need a more dynamic configuration, you should create a little script, like when configuring wmii. === Automatically putting clients on specific workspaces [[assign_workspace]] It is recommended that you match on window classes whereever possible because some applications first create their window and then care about setting the correct title. Firefox with Vimperator comes to mind, as the window starts up being named Firefox and only when Vimperator is loaded, the title changes. As i3 will get the title as soon as the application maps the window (mapping means actually displaying it on the screen), you’d need to have to match on Firefox in this case. You can prefix or suffix workspaces with a `~` to specify that matching clients should be put into floating mode. If you specify only a `~`, the client will not be put onto any workspace, but will be set floating on the current one. *Syntax*: ------------------------------------------------------------ assign ["]window class[/window title]["] [→] [~ | workspace] ------------------------------------------------------------ *Examples*: ---------------------- assign urxvt 2 assign urxvt → 2 assign "urxvt" → 2 assign "urxvt/VIM" → 3 assign "gecko" → ~4 assign "xv/MPlayer" → ~ ---------------------- === Automatically starting applications on startup By using the +exec+ keyword outside a keybinding, you can configure which commands will be performed by i3 on the first start (not when reloading inplace however). The commands will be run in order. *Syntax*: ------------ exec command ------------ *Examples*: -------------------------------- exec sudo i3status | dzen2 -dock -------------------------------- === Automatically putting workspaces on specific screens [[workspace_screen]] If you use the assigning of clients to workspaces and start some clients automatically, it might be handy to put the workspaces on specific screens. Also, the assignment of workspaces to screens will determine the workspace which i3 uses for a new screen when adding screens or when starting (e.g., by default it will use 1 for the first screen, 2 for the second screen and so on). *Syntax*: ---------------------------------- workspace output ---------------------------------- The output is the name of the RandR output you attach your screen to. On a laptop, you might have VGA1 and LVDS1 as output names. You can see the available outputs by running +xrandr --current+. *Examples*: --------------------------- workspace 1 output LVDS1 workspace 5 output VGA1 --------------------------- === Named workspaces If you always have a certain arrangement of workspaces, you might want to give them names (of course UTF-8 is supported): *Syntax*: --------------------------------------- workspace workspace output name --------------------------------------- For more details about the output-part of this command, see above. *Examples*: -------------------------- workspace 1 www workspace 2 work workspace 3 i ♥ workspaces -------------------------- === Changing colors You can change all colors which i3 uses to draw the window decorations and the bottom bar. *Syntax*: -------------------------------------------- colorclass border background text -------------------------------------------- Where colorclass can be one of: client.focused:: A client which currently has the focus. client.focused_inactive:: A client which is the focused one of its container, but it does not have the focus at the moment. client.unfocused:: A client which is not the focused one of its container. client.urgent:: A client which has its urgency hint activated. bar.focused:: The current workspace in the bottom bar. bar.unfocused:: All other workspaces in the bottom bar. bar.urgent:: A workspace which has at least one client with an activated urgency hint. Colors are in HTML hex format, see below. *Examples*: -------------------------------------- # class border backgr. text client.focused #2F343A #900000 #FFFFFF -------------------------------------- Note that for the window decorations the color around the child window is the background color and the border color is only the two thin lines at the top of the window. === Interprocess communication i3 uses unix sockets to provide an IPC interface. At the moment, this interface is only useful for sending commands. To enable it, you have to configure a path where the unix socket will be stored. The default path is +/tmp/i3-ipc.sock+. *Examples*: ---------------------------- ipc-socket /tmp/i3-ipc.sock ---------------------------- You can then use the i3-msg command to perform any command listed in the next section. === Disable focus follows mouse If you have a setup where your mouse usually is in your way (like a touchpad on your laptop which you do not want to disable completely), you might want to disable focus follows mouse and control focus only by using your keyboard. The mouse will still be useful inside the currently active window (for example to click on links in your browser window). *Syntax*: ---------------------------- focus_follows_mouse ---------------------------- *Examples*: ---------------------- focus_follows_mouse no ---------------------- == List of commands === Manipulating layout To change the layout of the current container to stacking, use +s+, for default use +d+ and for tabbed, use +T+. To make the current client (!) fullscreen, use +f+, to make it floating (or tiling again) use +t+: *Examples*: -------------- bindsym Mod1+s s bindsym Mod1+l d bindsym Mod1+w T # Toggle fullscreen bindsym Mod1+f f # Toggle floating/tiling bindsym Mod1+t t -------------- === Focussing/Moving/Snapping clients/containers/screens To change the focus, use one of the +h+, +j+, +k+ and +l+ commands, meaning respectively left, down, up, right. To focus a container, prefix it with +wc+, to focus a screen, prefix it with +ws+. The same principle applies for moving and snapping, just prefix the command with +m+ when moving and with +s+ when snapping: *Examples*: ---------------------- # Focus clients on the left, bottom, top, right: bindsym Mod1+j h bindsym Mod1+k j bindsym Mod1+j k bindsym Mod1+semicolon l # Move client to the left, bottom, top, right: bindsym Mod1+j mh bindsym Mod1+k mj bindsym Mod1+j mk bindsym Mod1+semicolon ml # Snap client to the left, bottom, top, right: bindsym Mod1+j sh bindsym Mod1+k sj bindsym Mod1+j sk bindsym Mod1+semicolon sl # Focus container on the left, bottom, top, right: bindsym Mod3+j wch … ---------------------- === Changing workspaces/moving clients to workspaces To change to a specific workspace, the command is just the number of the workspace, e.g. +1+ or +3+. To move the current client to a specific workspace, prefix the number with an +m+. Furthermore, you can switch to the next and previous workspace with the commands +nw+ and +pw+, which is handy for example if you have workspace 1, 3, 4 and 9 and you want to cycle through them with a single key combination. *Examples*: ------------------------- bindsym Mod1+1 1 bindsym Mod1+2 2 ... bindsym Mod1+Shift+1 m1 bindsym Mod1+Shift+2 m2 ... bindsym Mod1+o nw bindsym Mod1+p pw ------------------------- [[resizingconfig]] === Resizing columns/rows If you want to resize columns/rows using your keyboard, you can use the +resize+ command, I recommend using it inside a so called +mode+ (you need to use the new lexer/parser for that, so pass +-l+ to i3 when starting): .Example: Configuration file, defining a mode for resizing ---------------------------------------------------------------------- mode "resize" { # These bindings trigger as soon as you enter the resize mode # They resize the border in the direction you pressed, e.g. # when pressing left, the window is resized so that it has # more space on its left bindsym n resize left -10 bindsym Shift+n resize left +10 bindsym r resize bottom +10 bindsym Shift+r resize bottom -10 bindsym t resize top -10 bindsym Shift+t resize top +10 bindsym d resize right +10 bindsym Shift+d resize right -10 bind 36 mode default } # Enter resize mode bindsym Mod1+r mode resize ---------------------------------------------------------------------- === Jumping to specific windows Especially when in a multi-monitor environment, you want to quickly jump to a specific window, for example while currently working on workspace 3 you may want to jump to your mailclient to mail your boss that you’ve achieved some important goal. Instead of figuring out how to navigate to your mailclient, it would be more convenient to have a shortcut. *Syntax*: ---------------------------------------------------- jump ["]window class[/window title]["] jump workspace [ column row ] ---------------------------------------------------- You can either use the same matching algorithm as in the +assign+ command (see above) or you can specify the position of the client if you always use the same layout. *Examples*: -------------------------------------- # Get me to the next open VIM instance bindsym Mod1+a jump "urxvt/VIM" -------------------------------------- === VIM-like marks (mark/goto) [[vim_like_marks]] This feature is like the jump feature: It allows you to directly jump to a specific window (this means switching to the appropriate workspace and setting focus to the windows). However, you can directly mark a specific window with an arbitrary label and use it afterwards, that is, you do not need to ensure that your windows have unique classes or titles and you do not need to change your configuration file. As the command needs to include the label with which you want to mark the window, you cannot simply bind it to a key (or, you could bind it to a key and only use the set of labels for which you created bindings). +i3-input+ is a tool created for this purpose: It lets you input a command and sends the command to i3. It can also prefix this command and display a custom prompt for the input dialog. *Syntax*: ----------------- mark goto ----------------- *Examples*: --------------------------------------- # Read 1 character and mark the current window with this character bindsym Mod1+m exec i3-input -p 'mark ' -l 1 -P 'Mark: ' # Read 1 character and go to the window with the character bindsym Mod1+g exec i3-input -p 'goto ' -l 1 -P 'Goto: ' --------------------------------------- === Traveling the focus stack This mechanism can be thought of as the opposite of the +jump+ command. It travels the focus stack and jumps to the window you focused before. *Syntax*: -------------- focus [number] | floating | tilling | ft -------------- Where +number+ by default is 1 meaning that the next client in the focus stack will be selected. The special values have the following meaning: floating:: The next floating window is selected. tiling:: The next tiling window is selected. ft:: If the current window is floating, the next tiling window will be selected and vice-versa. === Changing border style To change the border of the current client, you can use +bn+ to use the normal border (including window title), +bp+ to use a 1-pixel border (no window title) and +bb+ to make the client borderless. There also is +bt+ which will toggle the different border styles. *Examples*: ------------------ bindsym Mod1+t bn bindsym Mod1+y bp bindsym Mod1+u bb ------------------ [[stack-limit]] === Changing the stack-limit of a container If you have a single container with a lot of windows inside (say, more than 10), the default layout of a stacking container can get a little unhandy. Depending on your screen’s size, you might end up only using half of the titlebars of each window in the container. Using the +stack-limit+ command, you can limit the amount of rows or columns in a stacking container. i3 will create columns or rows (depending on what you limited) automatically as needed. *Syntax*: -------------------------------- stack-limit -------------------------------- *Examples*: ------------------- # I always want to have two window titles in one line stack-limit cols 2 # Not more than 5 rows in this stacking container stack-limit rows 5 ------------------- image:stacklimit.png[Container limited to two columns] === Reloading/Restarting/Exiting You can make i3 reload its configuration file with +reload+. You can also restart i3 inplace with the +restart+ command to get it out of some weird state (if that should ever happen) or to perform an upgrade without having to restart your X session. However, your layout is not preserved at the moment, meaning that all open windows will be in a single container in default layout. To exit i3 properly, you can use the +exit+ command, however you don’t need to (e.g., simply killing your X session is fine aswell). *Examples*: ---------------------------- bindsym Mod1+Shift+r restart bindsym Mod1+Shift+w reload bindsym Mod1+Shift+e exit ---------------------------- == Multiple monitors [[multi_monitor]] As you can read in the goal list on its website, i3 was specifically developed with Xinerama (support for multiple monitors) in mind. This section will explain how to handle multiple monitors. When you have only one monitor, things are simple. You usually start with workspace 1 on your monitor and open new ones as you need them. When you have more than one monitor, each monitor will get an initial workspace, say the first gets 1, the second gets 2 and a possible third would get 3. When you switch to a workspace on a different screen, i3 will switch to that screen and then switch to the workspace. This way, you don’t need shortcuts to switch to a specific screen and remember where you put which workspace. New workspaces will be opened on the screen you currently are on. There is no possiblity to have a screen without workspaces. The idea to make workspaces global is due to the observation that most users have a very limited set of workspaces on their additional monitors, often using them for a specific task (browser, shell) or for monitoring several things (mail, IRC, syslog, …). Thus, using one workspace on one monitor and "the rest" on the other monitors often makes sense. However, as you can create unlimited workspaces in i3 and tie them to specific screens, you can have the "traditional" approach of having X workspaces per screen by changing your configuration (using modes, for example). === Configuring your monitors To help you get going if you never did multiple monitors before, here comes a short overview of the xrandr options which are probably of interest for you. It is always useful to get an overview of the current screen configuration, so just run "xrandr" and you will get an output like the following: -------------------------------------------------------------------------------------- $ xrandr Screen 0: minimum 320 x 200, current 1280 x 800, maximum 8192 x 8192 VGA1 disconnected (normal left inverted right x axis y axis) LVDS1 connected 1280x800+0+0 (normal left inverted right x axis y axis) 261mm x 163mm 1280x800 60.0*+ 50.0 1024x768 85.0 75.0 70.1 60.0 832x624 74.6 800x600 85.1 72.2 75.0 60.3 56.2 640x480 85.0 72.8 75.0 59.9 720x400 85.0 640x400 85.1 640x350 85.1 -------------------------------------------------------------------------------------- Several things are important here: You can see that +LVDS1+ is connected (of course, it is the internal flat panel) but +VGA1+ is not. If you have connected a monitor to one of the ports but xrandr still says "disconnected", you should check your cable, monitor or graphics driver. Furthermore, the maximum resolution you can see at the end of the first line is the maximum combined resolution of your monitors. By default, it is usually too low and has to be increased by editing +/etc/X11/xorg.conf+. So, say you connected VGA1 and want to use it as an additional screen: ------------------------------------------- xrandr --output VGA1 --auto --left-of LVDS1 ------------------------------------------- This command lets xrandr try to find out the native resolution of the device connected to +VGA1+ and configures it to the left of your internal flat panel. When running "xrandr" again, the output looks like this: ----------------------------------------------------------------------------------------- $ xrandr Screen 0: minimum 320 x 200, current 2560 x 1024, maximum 8192 x 8192 VGA1 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 338mm x 270mm 1280x1024 60.0*+ 75.0 1280x960 60.0 1152x864 75.0 1024x768 75.1 70.1 60.0 832x624 74.6 800x600 72.2 75.0 60.3 56.2 640x480 72.8 75.0 66.7 60.0 720x400 70.1 LVDS1 connected 1280x800+1280+0 (normal left inverted right x axis y axis) 261mm x 163mm 1280x800 60.0*+ 50.0 1024x768 85.0 75.0 70.1 60.0 832x624 74.6 800x600 85.1 72.2 75.0 60.3 56.2 640x480 85.0 72.8 75.0 59.9 720x400 85.0 640x400 85.1 640x350 85.1 ----------------------------------------------------------------------------------------- Please note that i3 uses exactly the same API as xrandr does, so it will see only what you can see in xrandr. See also <> for more examples of multi-monitor setups. === Interesting configuration for multi-monitor environments There are several things to configure in i3 which may be interesting if you have more than one monitor: 1. You can specify which workspace should be put on which screen. This will allow you to have a different set of workspaces when starting than just 1 for the first monitor, 2 for the second and so on. See <>. 2. If you want some applications to generally open on the bigger screen (MPlayer, Firefox, …), you can assign them to a specific workspace, see <>. 3. If you have many workspaces on many monitors, it might get hard to keep track of which window you put where. Thus, you can use vim-like marks to quickly switch between windows. See <>. == i3 and the rest of your software world === Displaying a status line A very common thing amongst users of exotic window managers is a status line at some corner of the screen. It is an often superior replacement of the widget approach you have in the task bar of a traditional desktop environment. If you don’t already have your favorite way of generating such a status line (self-written scripts, conky, …), then i3status is the recommended tool for this task. It was written in C with the goal to have as little syscalls as possible to reduce the time your CPU is waken up from sleep states. Regardless of which application you use to generate the status line, you want to make sure that the application does one of the following things: 1. Register as a dock window using EWMH hints. This will make i3 position the window above the workspace bar but below every other client. This is the recommended way, but for example in case of dzen2 you need to check out the source of dzen2 from subversion, because the -dock option is not present in the released versions. 2. Overlay the internal workspace bar. This method will not waste any space in the workspace bar. However, it is a rather hackish way. Just configure the output window to be over your workspace bar (say -x 200 and -y 780 if your screen is 800 px height). The planned solution for this problem is to make the workspace bar optional and switch to dzen2 (for example) completely (it will contain the workspaces then). === Giving presentations (multi-monitor) When giving a presentation, you typically want the audience to see what you see on your screen and then go through a series of slides (if the presentation is simple). For more complex presentations, you might want to have some notes which only you can see on your screen, while the audience can only see the slides. [[presentations]] ==== Case 1: everybody gets the same output This is the rather easy case. You connect your computer to the video projector, turn on both (computer and video projector) and configure your X server to clone the internal flat panel of your computer to the video output: ----------------------------------------------------- xrandr --output VGA1 --mode 1024x768 --same-as LVDS1 ----------------------------------------------------- i3 will then use the lowest common subset of screen resolutions, the rest of your screen will be left untouched (so it will show the X background). So, in our example, this would be 1024x768 (my notebook has 1280x800). ==== Case 2: you can see more than your audience This case is a bit harder. First of all, you should configure the VGA output somewhere near your internal flat panel, say right of it: ----------------------------------------------------- xrandr --output VGA1 --mode 1024x768 --right-of LVDS1 ----------------------------------------------------- Now, i3 will put a new workspace (depending on your settings) on the new screen and you are in multi-monitor mode (see <>). Because i3 is not a compositing window manager, there is no possibility to display a window on two screens at the same time. Instead, you presentation software needs to do this job (that is, open a window on each screen with the same contents).