OSC 50 — Set font

frame

OSC introducer: \x1b] ESC ] (0x1B 0x5D)

terminator (ST|BEL): ST \x1b\ · BEL \x07

parameters / subcommands

gotchas

• The SPEC SYNTAX differs: xterm expects an XLFD or '#N' index; iTerm2 uses its own font-name form. The same OSC 50 is not portable between them.
• OSC 50 has also been used by some terminals (and DEC) for other purposes historically; treat support as terminal-specific and feature-detect.
• The query form is an xterm convention; do not rely on iTerm2 answering it.
• Changing the font may resize cells and reflow the screen; expect a resize event.
• Over tmux/ssh the sequence must be passed through to the outer terminal.

provenance

• source: https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
• version: xterm ctlseqs, patch #410, 2026/04/19
• retrieved: 2026-05-29 · updated: 2026-05-29T00:00:00Z

per-fact attribution:

• #xterm — https://invisible-island.net/xterm/ctlseqs/ctlseqs.html xterm ctlseqs: Ps = 5 0 -> Set/query font. Pt is a font name (XLFD) or '#N' to select font N from the configured list; a query reports the current font.
• #iterm2 — https://iterm2.com/documentation-escape-codes.html iTerm2 documents OSC 50 to set the session font (e.g. OSC 50 ; <font spec> ST), with its own spec syntax distinct from xterm's XLFD.

see also

• terminal-osc/1337
• terminal-osc/4