image-type

image-type

Detect the image type of a Buffer/Uint8Array

See the file-type module for more file types.

Install

$ npm install --save image-type

Usage

Node.js

var readChunk = require('read-chunk'); // npm install read-chunk
var imageType = require('image-type');
var buffer = readChunk.sync('unicorn.png', 0, 12);

imageType(buffer);
//=> png

or from a remote location:

var http = require('http');
var imageType = require('image-type');
var url = 'http://assets-cdn.github.com/images/spinners/octocat-spinner-32.gif';

http.get(url, function (res) {
	res.once('data', function (chunk) {
		res.destroy();
		console.log(imageType(chunk));
		//=> gif
	});
});

Browser

var xhr = new XMLHttpRequest();
xhr.open('GET', 'unicorn.png');
xhr.responseType = 'arraybuffer';

xhr.onload = function () {
	imageType(new Uint8Array(this.response));
	//=> png
};

xhr.send();

API

imageType(buffer)

Returns an object (or null when no match) with:

• ext - one of the supported file types
• mime - the MIME type

buffer

Type: buffer (Node.js), uint8array

It only needs the first 12 bytes.

CLI

$ npm install --global image-type

$ image-type --help

  Usage
    image-type <filename>
    cat <filename> | image-type

  Example
    cat unicorn.png | image-type
    png

Supported file types

• jpg
• png
• gif
• webp
• tif
• bmp
• jxr
• psd

SVG isn't included as it requires the whole file to be read, but you can get it here.

License

MIT © Sindre Sorhus