DECSET 47 — Alternate screen buffer (legacy)

CSI ? 47 h switches to the alternate screen buffer; CSI ? 47 l switches back to the normal buffer. This is the original alt-screen mode: unlike 1049 it does NOT save/restore the cursor or clear the alt buffer on entry, so it is largely superseded by 1047/1048/1049.

aka: alternate screen · alt buffer · DECSET 47 · ?47h / ?47l · legacy alt screen

frame

DEC-private-mode introducer: \x1b[? ESC [ ? (0x1B 0x5B 0x3F)

terminator (none): ST · BEL

parameters / subcommands

id	name	bytes (ST)	meaning
set	Enable (DECSET)	\x1b[?47h	CSI ? 47 h switches output to the alternate screen buffer (the normal buffer's contents are preserved but hidden). It does NOT save the cursor or clear the alt buffer.
reset	Disable (DECRST)	\x1b[?47l	CSI ? 47 l switches back to the normal screen buffer, revealing its preserved contents.

gotchas

Mode 47 is the LEGACY alt-screen: it does NOT save/restore the cursor (use 1048 for that) and does NOT clear the alt buffer on entry/exit (1047 clears on exit). Most programs should use 1049 instead, which combines save-cursor + clear + switch.
Switching with 47 alone can leave stale content on the alt buffer from a previous use; clear it explicitly (CSI 2 J) if needed.
Mismatched enter/leave (47 vs 1049) between a program and its children can strand you on the wrong buffer.
tmux/screen track alt-screen state; mixing 47 and 1049 inside a multiplexer can confuse it.
Prefer DECSET 1049 for new code; 47 exists mainly for compatibility with old programs.

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:

#summary — https://invisible-island.net/xterm/ctlseqs/ctlseqs.html xterm ctlseqs: Ps = 4 7 -> Use Alternate Screen Buffer. (This mode is the legacy form; it does not save the cursor or clear on switch, unlike 1047/1049.)

DECSET 47 — Alternate screen buffer (legacy)

frame

parameters / subcommands

gotchas

provenance

see also