Create Retro ASCII Text Art with BitmapIt JavaScript

BitmapIt is a lightweight JavaScript library that transforms plain text into customizable bitmap-style ASCII art representations.

It’s ideal for creating retro terminal aesthetics, game interfaces, and nostalgic text displays in web applications.

Features:

• Customizable display characters (e.g., blocks, symbols)
• Adjustable character width, height, and inter-character spacing
• Simple, clean API for defining fonts and generating text
• HTML output with custom foreground and background colors
• Responsive character rendering (scales defined patterns)
• Zero external dependencies

See it in action:

How to use it:

1. Install BitmapIt and import it into your project.

# NPM
$ npm install bitmapit

import { BitmapFontGenerator, defaultFont } from 'bitmapit';

2. Or, for direct browser use

<script type="module">
  import { BitmapFontGenerator, defaultFont } from './public/bitmapit.js';
</script>

3. Initialize the Bitmap generator.

const generator = new BitmapFontGenerator();

4. Load default character patterns.

// BitmapIt comes with a 'defaultFont' you can use.
// 'defaultFont' is an object where keys are characters
// and values are 2D arrays (0 for off, 1 for on).
Object.entries(defaultFont).forEach(([char, pattern]) => {
  generator.defineCharacter(char, pattern);
});

5. Generate and display ASCII art.

const bitmap = generator.generateText('CSSSCRIPT');
console.log(generator.toAscii(bitmap));

6. Or get HTML.

const htmlOutput = generator.toHtml(bitmap, {
  color: '#39ff14', // Neon green
  backgroundColor: '#111111' // Dark gray
});
document.getElementById('myRetroDisplay').innerHTML = htmlOutput;

7. Available options for the BitmapFontGenerator() method.

• width: Width of each character cell.
• height: Height of each character cell.
• spacing: Space (in “pixel” units) between characters.
• onChar: Character used for a “lit” pixel.
• offChar: Character for an “unlit” pixel.
• color: Default text color for HTML output.
• backgroundColor: Default background for HTML.

BitmapFontGenerator({
  width: 8,
  height: 8,
  spacing: 1,
  onChar: '█',
  offChar: ' ',
  color: '#ffffff',
  backgroundColor: 'transparent',
})

8. Defines how a character looks.

• char (String): The character (e.g., ‘A’, ‘!’, ‘7’). Case-insensitive internally.
• pattern (Array of Arrays): A 2D array of 0s and 1s (or false and true) representing the pixel data. The library will scale this pattern to fit the width and height set on the generator.

// defineCharacter(char, pattern)
generator.defineCharacter('T', [
  [1,1,1],
  [0,1,0],
  [0,1,0]
]);

9. One-step text generation and formatting.

generator.createText(text, {
  html: true, // outputs HTML or not
})

10. Update character dimensions.

generator.setDimensions(width, height)

11. Modify character spacing.

generator.setSpacing(spacing)