How to show local picture in web page?

Question

I need to show a picture on web page without uploading it. something like

Answer 1

You can do that easily using FileReader.readAsDataURL(). The user chooses an image and you can display it without needing to upload it.

For more info see https://developer.mozilla.org/en-US/docs/Web/API/FileReader/readAsDataURL

Here is the code:

function previewFile() {
    // Where you will display your image
    var preview = document.querySelector('img');
    // The button where the user chooses the local image to display
    var file = document.querySelector('input[type=file]').files[0];
    // FileReader instance
    var reader  = new FileReader();

    // When the image is loaded we will set it as source of
    // our img tag
    reader.onloadend = function () {
      preview.src = reader.result;
    }

    
    if (file) {
      // Load image as a base64 encoded URI
      reader.readAsDataURL(file);
    } else {
      preview.src = "";
    }
  }