SGR 73 / 74 / 75 — Superscript / Subscript / Neither

Byte forms

Every common string-literal form so you can paste-and-search either direction.

Description

Three SGR codes outside the historical ECMA-48 vocabulary (which stops at SGR 65) that **mintty** introduced ~2017 and that **Kitty 0.32+**, **WezTerm 20240128+**, **foot 1.16+**, **iTerm2 3.5+** picked up afterwards. They are the *attribute* counterpart to the Unicode superscript / subscript blocks (U+2070–U+209F) — instead of substituting alternative glyphs, the terminal renders the **current** glyphs at smaller scale and raised / lowered baseline. **Codes** - `\x1b[73m` — **superscript**. Following characters render at ~75% size, baseline raised to roughly the cap-height line. - `\x1b[74m` — **subscript**. Following characters render at ~75% size, baseline lowered. - `\x1b[75m` — **neither**. Cancel both. Distinct from `\x1b[0m` (which also cancels every other attribute). **Why this matters** - *Math output* — write `H₂O` as `H\x1b[74m2\x1b[75mO` rather than `H\u2082O` (the latter only works if your output font has the subscript codepoints, many monospaced fonts don't). - *Footnotes* — render `text¹` from `text\x1b[73m1\x1b[75m` and remain searchable / copy-pasteable as plain digits. - *Chemistry / units* — `m²`, `m³`, `kg·m·s⁻¹` all render in monospace without font-substitution gymnastics. - *Diff output* — `git --color-words` and similar tools can use sub/super to mark insertion / deletion positions without disturbing the source line. **Constraints** - The attributes are **mutually exclusive** in spec: emitting `\x1b[73m` while subscript is active should toggle to superscript, not stack. Real emulators implement this correctly (last one wins). - **No nesting** — there is no SGR for 'super-superscript'. Terminals fall back to single-level rendering. - **Copy / paste preserves the codepoints** as written, not the rendered glyph — so `H\x1b[74m2\x1b[75mO` round-trips back to `H2O` (with the escape codes stripped by clipboard). This is *correct* for plain-text round-trips but means you can't rely on visual super/sub to communicate semantic super/sub to downstream tools that don't honour SGR — use Unicode for that. - **Width math** — subscript / superscript characters still occupy 1 cell width on the grid; the smaller glyphs don't change column alignment. This is important for TUI layout: a labelled axis like `10²` is still 3 cells wide. **Coverage**: **Kitty** (≥ 0.32) + **WezTerm** (≥ 20240128) + **foot** (≥ 1.16) + **iTerm2** (≥ 3.5) + **mintty** (≥ 3.4) = full. **Ghostty** = full (since 1.0). **xterm** = partial (`patch #383+`, only with `cjkWidth: true`; off otherwise). **gnome-terminal** + **Konsole** + **Alacritty** + **Windows Terminal** + **cmd / ConPTY** + **macOS Terminal** + **Linux console** = silently consumed (the SGR is parsed but the renderer paints normal-size baseline glyphs). Reset (`\x1b[0m`) cancels both attributes everywhere.

Spec citation: mintty / Kitty terminal-graphics-protocol superscript-extension / xterm-ctlseqs patch #383

Parameters

Examples

# Write 'H2O' with the 2 as subscript.\nprintf 'H\\033[74m2\\033[75mO\\n'\n# Cite 'foo^1' with footnote marker.\nprintf 'see foo\\033[73m1\\033[75m for context.\\n'

import sys\nsys.stdout.write('Area: 10\\x1b[73m2\\x1b[75m m\\x1b[73m2\\x1b[75m\\n')   # 10² m²

// Render a sequence: x¹, x², x³ in monospace via SGR rather than Unicode.\nfor _, n := range []int{1, 2, 3} {\n    fmt.Printf(\"x\\x1b[73m%d\\x1b[75m \", n)\n}\nfmt.Println()

// Footnote marker that copy-pastes as plain digit.\nprocess.stdout.write('see ref' + '\\x1b[73m' + idx + '\\x1b[75m\\n');

/* Chemical formula with subscripts. */\nprintf(\"C\\x1b[74m6\\x1b[75mH\\x1b[74m12\\x1b[75mO\\x1b[74m6\\x1b[75m\\n\");

Terminal support

xterm

partial

Linux console (fbcon)

no

macOS Terminal.app

no

iTerm2

yes

Windows Terminal

no

cmd.exe / ConPTY

no

kitty

yes

alacritty

no

WezTerm

yes

Ghostty

yes

GNOME Terminal

no

Konsole

no

tmux

no

GNU screen

no

Related sequences

• SGR 3 — Italic
• SGR 1 — Bold / Increased intensity
• SGR 0 — Reset / Normal
• SGR 38;2;R;G;B — 24-bit truecolor foreground