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is-jpg

is-jpg Build Status

Check if a Buffer/Uint8Array is a JPEG image

Used by image-type.

Install

$ npm install --save is-jpg

Usage

Node.js
var readChunk = require('read-chunk'); // npm install read-chunk 
var isJpg = require('is-jpg');
var buffer = readChunk.sync('unicorn.jpg', 0, 3);
 
isJpg(buffer);
//=> true 
Browser
var xhr = new XMLHttpRequest();
xhr.open('GET', 'unicorn.jpg');
xhr.responseType = 'arraybuffer';
 
xhr.onload = function () {
    isJpg(new Uint8Array(this.response));
    //=> true 
};
 
xhr.send();

API

isJpg(buffer)

Accepts a Buffer (Node.js) or Uint8Array.

It only needs the first 3 bytes.

License

MIT © Sindre Sorhus