Table of Contents

Proprietary Escape Codes

iTerm2 supports several non-standard escape codes. These may not work properly in tmux or screen, and may have unknown effects on other terminal emulators. Proceed with caution.

The control sequences use the following notation:

  • ESC means "Escape" (hex code 0x1b) .
  • ST means either BEL (hex code 0x07) or ESC \\.
  • Spaces in control sequences are to be ignored.
  • Values in [brackets] are variable parameters, not literals.
  • OSC means ESC ]
  • CSI means ESC [
  • SP means a literal "space" character (not ignored!)

The OSC command 50 used to be used but it conflicts with xterm, so it is now 1337.

Report Foreground/Background Colors (OSC 4)

The xterm-defined OSC 4 control sequence has a mode where it reports the RGB value of a color. iTerm2 extends its reporting mode to add two additional color indices representing the default foreground and background color.

To get the background color:

OSC 4 ; -2; ? ST

And this gets the foreground color:

OSC 4 ; -1 ; ? ST

For background and foreground respectively, the terminal will write back:

OSC 4 ; -2 ; rgb : [red] / [green] / [blue] ST
OSC 4 ; -1 ; rgb : [red] / [green] / [blue] ST

Where [red], [green], and [blue] are either 2 or 4-digit hex values like 14a7 or ff. For 4-digit values, you can get an approximation of the 2-digit value by taking the first two digits.

Anchor (OSC 8)

VTE and iTerm2 support OSC 8 for defining hyperlinks, much like HTML's anchor tag.

OSC 8 ; [params] ; [url] ST

[params] consists of zero or more colon-delimited key-value pairs. A key-value pair is formatted as key=value. The only currently defined key is id. Two adjacent hyperlinks with the same URL but different ids will highlight separately when Command is pressed during hover.

If the url is absent then that ends the hyperlink. Typical usage would look like:

OSC 8 ; ; ST Link to example website OSC 8 ; ; ST

To open a link, hold Command and click the link.

Note: in iTerm2 version 3.4 and later, if the URL has the file scheme and a # fragment is present then the semantic history rules will apply for opening the file. It may optionally include a line number, like file:///tmp/file.txt#123 or line number and column number like file:///tmp/file.txt#123:45.

Set cursor shape

OSC 1337 ; CursorShape=[N] ST

where [N]=0, 1, or 2.

  • 0: Block
  • 1: Vertical bar
  • 2: Underline

Add this to your .vimrc to change cursor shape in insert mode:

let &t_SI = "\<Esc>]1337;CursorShape=1\x7"
let &t_EI = "\<Esc>]1337;CursorShape=0\x7"

This is derived from Konsole.

Set Mark

The "Set Mark" (cmd-shift-M) command allows you to record a location and then jump back to it later (with cmd-shift-J). The following escape code has the same effect as that command:

OSC 1337 ; SetMark ST

Steal Focus

To bring iTerm2 to the foreground:

OSC 1337 ; StealFocus ST

Clear Scrollback History

To erase the scrollback history:

OSC 1337 ; ClearScrollback ST

Set current directory

To inform iTerm2 of the current directory to help semantic history:

OSC 1337 ; CurrentDir=[current directory] ST

Post a notification

To post a notification:

OSC 9 ; [Message content goes here] ST

Change profile

To change the session's profile on the fly:

OSC 1337 SetProfile=[new profile name] ST

Copy to clipboard

To place text in the pasteboard:

OSC 1337 ; CopyToClipboard=[clipboard name] ST

Where name is one of "rule", "find", "font", or empty to mean the general pasteboard (which is what you normally want). After this is sent, all text received is placed in the pasteboard until this code comes in:

OSC 1337 ; EndCopy ST

Set window title and tab chrome background color

To set the window title and tab color use this escape sequence:

OSC 6 ; 1 ; bg ; red ; brightness ; [N] ST
OSC 6 ; 1 ; bg ; green ; brightness ; [N] ST
OSC 6 ; 1 ; bg ; blue ; brightness ; [N] ST

Replace [N] with a decimal value in 0 to 255.

Example in bash that turns the background purple:

echo -e "\033]6;1;bg;red;brightness;255\a"
echo -e "\033]6;1;bg;green;brightness;0\a"
echo -e "\033]6;1;bg;blue;brightness;255\a"

To reset the window title and tab color, use this code:

OSC 6 ; 1 ; bg ; * ; default ST

For example:

echo -e "\033]6;1;bg;*;default\a"

Change the color palette

To change the current session's colors use this code:

OSC 1337 ; SetColors=[key]=[value] ST

[key] gives the color to change. The accepted values are: fg bg bold link selbg selfg curbg curfg underline tab" black red green yellow blue magenta cyan white br_black br_red br_green br_yellow br_blue br_magenta br_cyan br_white

[value] gives the new color. The following formats are accepted:

  • RGB (three hex digits, like fff)
  • RRGGBB (six hex digits, like f0f0f0)
  • cs:RGB (like RGB but cs gives a color space)
  • cs:RRGGBB (like RRGGBB but cs gives a color space)

If a color space is given, it should be one of:

  • srgb (the standard sRGB color space)
  • rgb (the device-specific color space)
  • p3 (the standard P3 color space, whose gamut is supported on some newer hardware)

The following alternate schemes are also supported: * If key is preset then value should be the name of a color preset. * If key is tab then a value of default removes the tab color and restores it to the system default.

A second escape sequence is also supported, but its use is not recommended:

OSC P [n] [rr] [gg] [bb] ST

Replace [n] with:

  • `0`-`f` (hex) = ansi color
  • `g` = foreground
  • `h` = background
  • `i` = bold color
  • `j` = selection color
  • `k` = selected text color
  • `l` = cursor
  • `m` = cursor text

[rr], [gg], [bb] are 2-digit hex value (for example, "ff"). Example in bash that changes the foreground color blue:

echo -e "\033]Pg4040ff\033\\"


To add an annotation use on of these sequences:

OSC 1337 ; AddAnnotation=[message] ST
OSC 1337 ; AddAnnotation=[length] | [message] ST
OSC 1337 ; AddAnnotation=[message] | [length] | [x-coord] | [y-coord] ST
OSC 1337 ; AddHiddenAnnotation=[message] ST
OSC 1337 ; AddHiddenAnnotation=[length] | [message] ST
OSC 1337 ; AddHiddenAnnotation=[message] | [length] | [x-coord] | [y-coord] ST
  • `[message]`: The message to attach to the annotation.
  • `[length]`: The number of cells to annotate. Defaults to the rest of the line beginning at the start of the annotation.
  • `[x-coord]` and `[y-coord]`: The starting coordinate for the annotation. Defaults to the cursor's coordinate.

AddHiddenAnnotation does not reveal the annotation window at the time the escape sequence is received, while AddAnnotation opens it immediately.

Cursor Guide

OSC 1337 ; HighlightCursorLine=[boolean] ST

The [boolean] should be yes or no. This shows or hides the cursor guide.


OSC 1337 ; RequestAttention=[value] ST

The [value] should be yes to request attention by bouncing the dock icon indefinitely, once to bounce it a single time, or no to cancel a previous request. If it is fireworks then fireworks explode at the cursor's location.

Background Image

OSC 1337 ; SetBackgroundImageFile=[base64] ST

The value of [base64] is a base64-encoded filename to display as a background image. If it is an empty string then the background image will be removed. User confirmation is required as a security measure.

Report Cell Size

OSC 1337 ; ReportCellSize ST

The terminal responds with either:

OSC 1337 ; ReportCellSize=[height];[width] ST

Or, in newer versions:

OSC 1337 ; ReportCellSize=[height];[width];[scale] ST

[scale] gives the number of pixels (physical units) to points (logical units). 1.0 means non-retina, 2.0 means retina. It could take other values in the future.

[height] and [width] are floating point values giving the size in points of a single character cell. For example:

OSC 1337 ; ReportCellSize=17.50;8.00;2.0 ST

Copy to Pasteboard

You can place a string in the system's pasteboard with this sequence:

OSC 1337 ; Copy=:[base64] ST

Where [base64] is the base64-encoded string to copy to the pasteboard.

Report Variable

Each iTerm2 session has internal variables (as described in Scripting Fundamentals). This escape sequence reports a variable's value:

OSC 1337 ; ReportVariable=[base64] ST

Where [base64] is a base64-encoded variable name, like It responds with:

OSC 1337 ; ReportVariable=[base64] ST

Where [base64] is a base64-encoded value.


The badge has custom escape sequences described here.


For information on file downloads and inline images, see here.


To request the user select one or more files to upload, send:

OSC 1337 ; RequestUpload=format=[type] ST

In the future the [type] may be configurable, but for now it must always be tgz, which is a tar and gzipped file.

When iTerm2 receives this it will respond with a status of ok or abort followed by a newline. If the status is ok then it will be followed by a base-64 encoded tar.gz file.

If the user selects multiple files they will be placed in a directory within the tar file.

Set Touch Bar Key Labels

You can configure touch bar key labels for function keys and for the "status" button. The code used is:

OSC 1337 ; SetKeyLabel=[key]=[value] ST

Where [key] is one of F1, F2, ..., F24, to adjust a function key label; or it can be status to adjust the touch bar status button. You can also save and restore sets of key labels using a stack. To push the current key labels on the stack use:

OSC 1337 ; PushKeyLabels ST

To pop them:

OSC 1337 ; PopKeyLabels ST

You can optionally label the entry in the stack when you push so that pop will pop multiple sets of key labels if needed. This is useful if a program crashes or an ssh session exits unexpectedly. The corresponding codes with labels are:

OSC 1337 ; PushKeyLabels=[label] ST
OSC 1337 ; PopKeyLabels=[label] ST

Where [label] is an ASCII string that works best if it is unique in the stack.

Unicode Version

iTerm2 by default uses Unicode 9's width tables. The user can opt to use Unicode 8's tables with a preference (for backward compatibility with older locale databases). Since not all apps will be updated at the same time, you can tell iTerm2 to use a particular set of width tables with:

OSC 1337 ; UnicodeVersion=[n] ST

Where [n] is 8 or 9

You can push the current value on a stack and pop it off to return to the previous value by setting n to push or pop. Optionally, you may affix a label after push by setting n to something like push mylabel. This attaches a label to that stack entry. When you pop the same label, entries will be popped until that one is found. Set n to pop mylabel to effect this. This is useful if a program crashes or an ssh session ends unexpectedly.

File Transfer

OSC 1337 ; File=[args] ST

See Images for details.

Custom Control Sequences

iTerm2 allows scripts to define custom control sequences. See the Create Window example for a working demo. The control sequence is:

OSC 1337 ; Custom=id=[secret]:[pattern] ST

Where [secret] is a secret shared between the script implementing the control sequence and the program producing it, as a security measure to make it more difficult for untrusted text to invoke a custom control sequence. [pattern] is used to identify the sequence and may contain any parameters the script needs to handle it.

Shell Integration/FinalTerm

iTerm2's Shell Integration feature is made possible by proprietary escape sequences pioneered by the FinalTerm emulator. FinalTerm is defunct, but the escape sequences are documented here.


The goal of the FinalTerm escape sequences is to mark up a shell's output with semantic information about where the prompt begins, where the user-entered command begins, and where the command's output begins and ends.

[PROMPT]prompt% [COMMAND_START] ls -l
-rw-r--r-- 1 user group 127 May 1 2016 filename

Escape Sequences

FinalTerm originally defined various escape sequences in its original spec that are not supported by iTerm2 and are not described in this document. The best remaining references to these codes are in iTerm2's source code.


OSC 133 ; A ST

Sent just before start of shell prompt.


OSC 133 ; B ST

Sent just after end of shell prompt, before the user-entered command.


OSC 133 ; C ST

Sent just before start of command output. All text between FTCS_COMMAND_START and FTCS_COMMAND_EXECUTED at the time FTCS_COMMAND_EXECUTED is received excluding terminal whitespace is considered the command the user entered. It is expected that user-entered commands will be edited interactively, so the screen contents are captured without regard to how they came to contain their state. If the cursor's location is before (above, or if on the same line, left of) its location when FTCS_COMMAND_START was received, then the command will be treated as the empty string.


OSC 133 ; D ; [Ps] ST
OSC 133 ; D ST

The interpretation of this command depends on which FTCS was most recently received prior to FTCS_COMMAND_FINISHED.

This command may be sent after FTCS_COMMAND_START to indicate that a command was aborted. All state associated with the preceding prompt and the command until its receipt will be deleted. Either form is accepted for an abort. If the [Ps] argument is provided to an abort it will be ignored.

If this command is sent after FTCS_COMMAND_EXECUTED, then it indicates the end of command prompt. Only the first form with [Ps] should be used in this case. [Ps] is the command's exit status, a number in the range 0-255 represented as one or more ASCII decimal digits. A status of 0 is considered "success" and nonzero indicates "failure." The terminal may choose to indicate this visually.

If neither FTCS_COMMAND_START nor FTCS_COMMAND_EXECUTED was sent prior to FTCS_COMMAND_FINISHED it should be ignored.

iTerm2 Extensions

iTerm2 extends FinalTerm's suite of escape sequences.


OSC 1337 ; SetUserVar=[Ps1]=[Ps2] ST

Sets the value of a user-defined variable. iTerm2 keeps a dictionary of key-value pairs which may be used within iTerm2 as string substitutions. See Scripting Fundamentals for more information on variables and how they can be used.

[Ps1] is the key.

[Ps2] is the base64-encoded value.


Two forms are accepted. The second form is deprecated and should not be used:

OSC 1337 ; ShellIntegrationVersion=[Pn] ; [Ps] ST
OSC 1337 ; ShellIntegrationVersion=[Pn] ST

Reports the current version of the shell integration script.

[Pn] is the version.

[Ps] is the name of the shell (e.g., bash).

iTerm2 has a baked-in notion of the "current" version and if it sees a lower number the user will be prompted to upgrade. The version number is specific to the shell.


OSC 1337 ; RemoteHost=[Ps1]@[Ps2] ST

Reports the user name and hostname.

[Ps1] is username. [Ps2] is fully-qualified hostname.

The following synonym is available as a combination of RemoteHost and CurrentDir:

OSC 7 [Ps] ST

where [Ps] is a file URL with a hostname and a path, like file://


OSC 1337 ; CurrentDir=[Ps1] ST

Reports the current directory.

[PS1] is the current directory.

The following synonym is available as a combination of RemoteHost and CurrentDir:

OSC 7 ; [Ps] ST

where [Ps] is a file URL with a hostname and a path, like file://


OSC 1337 ; ClearCapturedOutput ST

Erases the current captured output.


CSI 0 SP q 

This will reset the cursor to its default appearance. This is an intentional deviation from the behavior of DEC virtual terminals.

Curly Underlines

CSI 4 : 3 m

This turns on curly underlines.

Extended Device Attributes

Report terminal name and version.

CSI > q

iTerm2 will respond with:

ESC P > | iTerm2 [version] ST

Where [version] is the version of iTerm2, such as 3.4.0.