Bookmarklet to download all images on a page

image_downloader.js

;(function() {
  var images = [].slice.call(document.querySelectorAll('img'))
  try {
    images.forEach(function(img) {
      downloadImage(img)
    })
  } catch (e) {
      alert("Download failed.");
      console.log('Download failed.', e);
  }
  
  function downloadImage(img) {
    var link = document.createElement('a')
    link.setAttribute('href', img.src)
    link.setAttribute('download', '')
    link.click()
  }
}).call(window);

image_downloader.txt

javascript:;(function() {var images = [].slice.call(document.querySelectorAll('img'));try {images.forEach(function(img){downloadImage(img)})} catch (e) {alert('Download failed.');console.log('Download failed.', e)}function downloadImage(img) {var link = document.createElement('a');link.setAttribute('href', img.src);link.setAttribute('download', '');link.click()}}).call(window);

Thx!
Did not work everywhere because of cross-origin loads (https://stackoverflow.com/questions/49474775/chrome-65-blocks-cross-origin-a-download-client-side-workaround-to-force-down) so I created a working version based on your snippet :)

How to execute this .js file on popup.html? Just trying to implement this into Chrome Extension :)

Works fine, but some pictures are not included into the download batch. I have to repeat the process several times, getting dup pictures, to the download the full set.

I adjusted this to wait a half second between requests and it runs a bit more reliably. I also include an example selector with a class specified. In var sel-'img.image-large', you can narrow your downloads to just those images with a particular class. Make sure to change the class name after the . to meet your specific case:

(function() {var sel='img.image-large',i=0; var images = [].slice.call(document.querySelectorAll(sel));try {images.forEach(function(img){downloadImage(img,i++)})} catch (e) {alert('Download failed.');console.log('Download failed.', e)}function downloadImage(img) {var link = document.createElement('a');link.setAttribute('href', img.src);link.setAttribute('download', ''); setTimeout( ()=>{link.click()}, i*500 ) }}).call(window);

A variant of the code above removing filtering by class... With var sel='img', all images will download:

(function() {var sel='img',i=0; var images = [].slice.call(document.querySelectorAll(sel));try {images.forEach(function(img){downloadImage(img,i++)})} catch (e) {alert('Download failed.');console.log('Download failed.', e)}function downloadImage(img) {var link = document.createElement('a');link.setAttribute('href', img.src);link.setAttribute('download', ''); setTimeout( ()=>{link.click()}, i*500 ) }}).call(window);

To be clear, just paste one of these "one-liners" into the console of a browser page and watch all the images of that page download in (fairly) rapid succession, one every 0.5 seconds to let the browser "breathe" a bit between downloads.