PNG2ICOjs is a simple and small (1.31KB minified) Javascript ES6 module that convert PNG files into ICO file. It should work on any Javascript environment including browsers.

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Installation & Usage

Right now I haven't deployed the library to any CDN yet. Please grab the script files in Release page. It is available in TypeScript and Javascript file.

To use the module, simply import it in your script:

import { PngIcoConverter } from "../src/png2icojs.js";

// ...

const inputs = [...files].map(file => ({
    png: file
}));

// Result is a Blob
const resultBlob1 = await converter.convertToBlobAsync(inputs); // Default mime type is image/x-icon
const resultBlob2 = await converter.convertToBlobAsync(inputs, "image/your-own-mime");

// Result is an Uint8Array
const resultArr = await converter.convertAsync(inputs);

You can check the demo at the Demo page.

API

The API exposes the PngIcoConverter class with many protected function so you can override them to your need.

Methods

PngIcoConverter exposes publicly the following methods:

• async convertToBlobAsync(inputs: IConvertInputItem[], mime = IcoMime): Promise<Blob>;

Convert PNG files into a ICO Blob with optional mime type. Default: image/x-icon.

• async convertAsync(inputs: IConvertInputItem[]): Promise<Uint8Array>;

Convert PNG files into a Uint8Array.

Input Options

IConvertInputItem has the following properties:

• png: the PNG file. Can be Blob or ArrayBuffer.

• bpp (optional, default 0): Bits per pixel. For the header of the ICO image. In my experiments, most apps just ignore this value altogether and use the value from PNG image.

• ignoreSize (optional, default false): Due to the size byte of ICO only has 1 byte, the maximum size of icons are 256px. However I have attemped to make an icon with 512px icon and it works so far. The library still throw an Error if your image size is more than 256px. Set this to true to ignore it.