Image to ASCII Art

ASCII art turns a photo into a grid of text characters chosen so their visual density mimics the image — dense characters like @ and # for dark areas, sparse ones like . and a plain space for light areas. It is one of the oldest tricks in computing, dating back to when text was the only display technology available, and it has never really gone away — terminal splash screens, retro-styled READMEs, and plain-text-only contexts all still use it.

The image is resized down to a small grid — one output character per sample point — and each sample's brightness is mapped onto a ramp of characters ordered from visually darkest to lightest. A bright pixel becomes a light character or a space; a dark pixel becomes a dense character. Colour is discarded entirely in the classic form, since a plain-text character has no colour of its own — only brightness survives the conversion.

• Clear, high-contrast subjects read far better than subtle, low-contrast photos — ASCII art has a fraction of the tonal range of a real image, so it needs strong differences to render recognisably.
• Simple compositions — a single subject against a plain background — convert more legibly than busy, detailed scenes, which turn into visual noise at low character resolution.
• Wide output widths give more characters to work with and therefore more visible detail, at the cost of the result no longer fitting a narrow terminal or chat window.

ASCII art depends entirely on being displayed in a monospace font, where every character occupies exactly the same width. Paste it somewhere that renders in a proportional font — most rich-text editors, many chat apps by default, most web pages — and the alignment collapses, since a narrow character like . and a wide one like @ no longer take up equal horizontal space. Code blocks, terminals, and plain-text areas that explicitly use a monospace font are the destinations where it renders correctly.