ASCII Art

What is ASCII Art?

ASCII art is the practice of creating visual images, diagrams, and decorative text using characters from the ASCII character set (or, in modern usage, the broader Unicode character set). It originated in the era of teletype and early computer terminals, where bitmap graphics were unavailable and all output was character-based. ASCII art spread through bulletin board systems (BBS), Usenet, email signatures, and early web pages in the 1980s and 1990s.

While classic ASCII art uses the 95 printable ASCII characters (U+0020–U+007E) — particularly letters, digits, slashes, underscores, and pipe characters — Unicode dramatically expanded the creative palette available to text-based artists with three key character ranges.

Unicode Box-Drawing Characters (U+2500–U+257F)

The Box Drawing block (128 characters) provides lines and corners for drawing rectangular diagrams, table borders, and flow charts entirely in text. These characters are drawn to align precisely with adjacent box-drawing characters, making them ideal for terminal user interfaces (TUIs), data tables, and tree displays.

┌─────────────────┐
│  Unicode Table  │
├──────┬──────────┤
│ Code │ Name     │
├──────┼──────────┤
│U+2500│ BOX DRAW │
│U+2502│ VERTICAL │
└──────┴──────────┘

Heavy and double-line variants (┃, ━, ╔, ╗, ╠, ╣) allow visual hierarchy in complex diagrams. Frameworks like rich (Python) and blessed use these characters extensively.

Unicode Block Elements (U+2580–U+259F)

The Block Elements range (32 characters) provides fractional block fills — upper half, lower half, left quarter, right quarter, and eight levels of vertical fill. These allow pixel-level approximation in a character grid, enabling grayscale images to be rendered in terminal output.

▓▒░ ← Full, medium, light shade
▄▀█ ← Lower half, upper half, full block

Modern terminal image viewers like catimg and viu use block elements to display photographs at quarter-cell resolution, giving the impression of twice the vertical resolution of the character grid.

Unicode Braille Patterns (U+2800–U+28FF)

The Braille Patterns block (256 characters) encodes all possible combinations of the 8 dots in a Braille cell. While designed for tactile display devices, these characters are also used by Unicode artists to achieve very high-resolution text art, since each Braille character can represent an 2×4 grid of on/off pixels — giving 8 "pixels" per character cell.

# Each Braille character is a 2x4 dot matrix
# Bit positions:  1 4
#                 2 5
#                 3 6
#                 7 8
# U+2800 = all dots off (blank)
# U+28FF = all 8 dots on (⣿)

Terminal art generators use Braille to render bitmap images at approximately 160 DPI equivalent in a standard 80×24 terminal.

Quick Facts