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Delete lines (DL)

Category: editing · Baseline: modern · Tags: ECMA-48 Standard, VT100 · Specification ↗

ESC [ N M
DL deletes N lines at the cursor row, scrolling lines below upward within the scroll region. The sequence is ESC [ N M (default N=1). Blank lines are inserted at the bottom margin. The complement of IL (insert lines).
How this is testedautomated
Write 3 lines, move to row 2, send \x1b[1M (DL 1), verify LINE3 moved up to row 1.

The same probe runs against headless backends (via Termless) and real terminal apps (via a daemon launched in each terminal). This lets us distinguish parser correctness from rendering correctness.

Analysis2026-04-06

Supported by 11 of 12 terminals (92%). Not supported by: vt100.js. Part of the Modern TUI baseline. Notes: vt100.js: DL (delete lines) not implemented in vt100.js baseline emulator.

Supported by 12 of 14 backends (86%)

Terminal Applications

TerminalVersionSupportNotes
iTerm23.6.9✓ yes
Ghostty1.3.1✓ yes
VS Code✓ yes
Warp✓ yes
Cursor✓ yes
Terminal.app✓ yes

Headless Backends

Parser correctness only — a means the parser accepts the sequence.

BackendVersionSupportNotes
Alacritty0.26.0✓ yes
Kitty0.40.0✓ yes
vterm0.2.0✓ yes
WezTerm0.1.0-fork.5✓ yes
xterm.js5.5.0✓ yes
vt100.js0.2.1✗ noDL (delete lines) not implemented in vt100.js baseline emulator