Instant Image Upload Preview | HTML & JavaScript

In this video we will learn how to preview an image before upload. How? Its easy we are going to use JavaScript's File Reader API to the file directly from the file input in a format which will allow us to view even before upload is done. To implement this functionality we will be using technologies such as HTML and Vanilla JS. How does it works? Here's a simplified explanation. JavaScript Provides an API for reading a file which we will be using to implement our preview script. 1. We have a file input which we will be used for selecting file. 2. Upon selection of file a FileReader object is initialized to read the file dataURL/base64 format. 3. After reading we replace the src attribute of image element. That's it. You've learnt how to make instant upload preview. Source Code : https://codepen.io/sidtheangel/pen/WVRgdR