Detect the image type of an ArrayBuffer/Uint8Array
See the file-type module for more file types and a CLI.
npm install image-type
import {readChunk} from 'read-chunk';
import imageType, {minimumBytes} from 'image-type';
const buffer = await readChunk('unicorn.png', {length: minimumBytes});
await imageType(buffer);
//=> {ext: 'png', mime: 'image/png'}
Or from a remote location:
import https from 'node:https';
import imageType, {minimumBytes} from 'image-type';
const url = 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg';
https.get(url, response => {
response.on('readable', () => {
(async () => {
const chunk = response.read(minimumBytes);
response.destroy();
console.log(await imageType(chunk));
//=> {ext: 'jpg', mime: 'image/jpeg'}
})();
});
});
const xhr = new XMLHttpRequest();
xhr.open('GET', 'unicorn.png');
xhr.responseType = 'arraybuffer';
xhr.onload = () => {
(async () => {
await imageType(new Uint8Array(this.response));
//=> {ext: 'png', mime: 'image/png'}
})();
};
xhr.send();
Returns an Promise<object> with:
ext - One of the supported file typesmime - The MIME typeOr undefined when there is no match.
Type: ArrayBuffer | Uint8Array
It only needs the first minimumBytes amount of bytes.
Type: number
The minimum amount of bytes needed to detect a file type. Currently, it's 4100 bytes, but it can change, so don't hardcode it.
jpgpnggifwebpflifcr2tifbmpjxrpsdicobpgjp2 - JPEG 2000jpm - JPEG 2000jpx - JPEG 2000heiccurdcm - DICOM Image FileSVG isn't included as it requires the whole file to be read, but you can get it here.