Built-in character sets
Defining a custom character set
Select Custom from the character set dropdown. A text field appears beneath it. Type the characters you want to use, ordered from darkest (fewest pixels, placed at low luminance) to lightest (most pixels, placed at high luminance). For example, the default fallback is .:-=+*#%@.
Any Unicode characters are accepted, including emoji, though monospace rendering of non-standard glyphs varies by font.
Font selection
Eight monospace fonts are available, each giving a distinct character to the output:- JetBrains Mono (default)
- IBM Plex Mono
- Space Mono
- Fira Code
- Source Code Pro
- Inconsolata
- DM Mono
- Courier Prime
- System mono — uses the operating system’s built-in monospace font
Font weight
The font weight slider runs from 100 (hairline) to 900 (black) in steps of 100. The default is 700 (bold). Lighter weights produce more open, airy output; heavier weights fill cells more densely and increase apparent contrast.Edge-aware characters
When you check Edge-aware chars, ASCII runs Sobel edge detection on the source image before rendering. At pixels where an edge is detected above the edge threshold, the tool substitutes one of four directional line characters:
At pixels below the edge threshold, the normal brightness-to-character mapping applies. You can tune the sensitivity with the Edge threshold slider in the Adjustments section.