Window title¶

Status: xterm.

OSC 0, 1, and 2 set the text an emulator shows in its window title bar, tab, or icon. They are the oldest OSCs in wide use and the one most shells emit by default.

Title Ops: OSC 0/1/2 label changes and applying saved labels on pop use xterm's Title Ops policy. Window Ops: reports and stack operations use the separate Window Ops policy. A pop involves both checks.

Syntax¶

OSC 0 ; Pt ST    set icon name and window title
OSC 1 ; Pt ST    set icon name
OSC 2 ; Pt ST    set window title

Pt is arbitrary text. Emulators differ on encoding: xterm interprets the string according to utf8Title, while most modern emulators assume UTF-8 unconditionally. Control bytes inside Pt are stripped or terminate the string; do not rely on either.

Behavior¶

The "icon name" is an X11 concept. On other platforms OSC 1 is usually ignored or aliased to the tab title.
Titles are per emulator window or tab, not per PTY. A title set by a program inside tmux is applied by tmux to the outer terminal only when set-titles is on, and tmux then formats it with set-titles-string.
Nothing restores the old title when a program exits. Shells that set the title on every prompt (bash PROMPT_COMMAND, zsh precmd) mask this; editors that set a title and are killed do not.

Title stack: XTWINOPS 22 and 23¶

xterm added a push/pop stack so an application can save and restore the title around its own changes:

CSI 22 ; 0 t    push icon name and title
CSI 22 ; 1 t    push icon name
CSI 22 ; 2 t    push title
CSI 23 ; 0 t    pop icon name and title
CSI 23 ; 1 t    pop icon name
CSI 23 ; 2 t    pop title

The stack is bounded (10 entries in xterm). See Window operations for the rest of XTWINOPS.

PushTitle and PopTitle govern the stack operations. Applying labels after a permitted pop also requires Title Ops: with allowTitleOps false, a normal pop consumes its entry but leaves the visible labels unchanged.

Title reports: XTWINOPS 20 and 21¶

CSI 20 t and CSI 21 t ask the terminal to report the icon name and title as OSC L Pt ST and OSC l Pt ST. xterm disables both by default (allowWindowOps) because the reply arrives as input: a program that first sets the title to a shell command and then requests it back has typed that command. Most emulators either do not implement the reports or answer with an empty title. Do not depend on them.

Title encoding modes¶

CSI > Pm t    XTSMTITLE: enable title encoding features
CSI > Pm T    XTRMTITLE: reset title encoding features

Each parameter selects one feature. The titleModes resource supplies a bitmask, with bit n corresponding to parameter n below.

Parameter	Feature
`0`	Set window/icon labels using hexadecimal
`1`	Report window/icon labels using hexadecimal
`2`	Set window/icon labels using UTF-8
`3`	Report window/icon labels using UTF-8

Without parameters, both sequences restore the compiled-in title-mode defaults. These settings select encoding; they do not grant permission to change or report labels. utf8Title also enables UTF-8 title input and EWMH label properties. See Title Ops policy for the distinction.

Probe¶

printf '\033]2;TDN title probe\033\\'
tools/sendosc title 'TDN title probe'
printf '\033[22;2t'; printf '\033]2;pushed\033\\'; sleep 2; printf '\033[23;2t'

The third line should end with the title that was current before pushed.

Sources¶

Separately tracked behavior¶

Hexadecimal title input¶

Feature ID: title-modes-hex-input. titleModes/XTSMTITLE hexadecimal input decoding.

Hexadecimal title reports¶

Feature ID: title-modes-hex-reports. titleModes hexadecimal report encoding under the report permission.

UTF-8 title input mode¶

Feature ID: title-modes-utf8-input. titleModes UTF-8 input decoding and reset semantics.

UTF-8 title report mode¶

Feature ID: title-modes-utf8-reports. titleModes UTF-8 report encoding under the report permission.

Title encoding configuration¶

Feature ID: resource-title-modes. titleModes resource default and XTSMTITLE/XTRMTITLE state changes.

UTF-8 Titles setting¶

Feature ID: resource-utf8-title. utf8Title resource and utf8-title menu/action with locale and allowC1Printable interaction.

ICCCM and EWMH title properties¶

Feature ID: x11-utf8-title-properties. Synchronize WM_NAME/WM_ICON_NAME and UTF-8 EWMH labels; delete stale properties when encoding changes.

Title input normalization¶

Feature ID: title-input-normalization. Normalize title control characters and validate hex input like xterm ChangeGroup.

Title input length limits¶

Feature ID: title-input-byte-limit. Reject overlong title input before decoding, rather than truncating it.

Suppress redundant title updates¶

Feature ID: resource-same-name. sameName avoids redundant title/icon property changes.

Compatibility¶

Feature support by terminal. Imported claims have not been reverified; unknown is not unsupported.
Feature / stable ID	Alacritty	Apple Terminal	ConPTY (conhost)	Contour	DomTerm	foot	Ghostty	iTerm2	kitty	Konsole	mintty	mlterm	PuTTY	Revenant	RLogin	st	tmux	rxvt-unicode	VTE	wayst	WezTerm	Windows Terminal	xterm	xterm.js
22/23 title stack `csi-22-23-t-title-stack`	SupportedImported · unverified	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	Unknown	Unknown	SupportedImported · unverified	Unknown	Unknown	Partial	Unknown	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified
OSC 0/2 set `osc-0-2-title`	SupportedImported · unverified	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	Unknown	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified	SupportedImported · unverified
OSC 1 icon `osc-1-icon-name`	Unknown	Unknown	Unknown	Unknown	Unknown	PartialImported · unverified	Unknown	Unknown	PartialImported · unverified	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	PartialImported · unverified	Unknown	Unknown	Unknown	SupportedImported · unverified	Unknown
20/21 report `csi-20-21-t-title-reports`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	PartialImported · unverified	Unknown
XTRMTITLE reset title modes `csi-xtrmtitle`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
XTSMTITLE set title modes `csi-xtsmtitle`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Set icon name and window title `osc-0-title-icon`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Set window title `osc-2-title`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Hexadecimal title input `title-modes-hex-input`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Hexadecimal title reports `title-modes-hex-reports`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
UTF-8 title input mode `title-modes-utf8-input`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
UTF-8 title report mode `title-modes-utf8-reports`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Title encoding configuration `resource-title-modes`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
UTF-8 Titles setting `resource-utf8-title`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
ICCCM and EWMH title properties `x11-utf8-title-properties`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Title input normalization `title-input-normalization`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Title input length limits `title-input-byte-limit`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown
Suppress redundant title updates `resource-same-name`	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown	Unknown