How to download an image using Selenium (any version)?

Question

I was wondering, how can one use selenium/webdriver to download an image for a page. Assuming that the user session is required to download the image hence having pure URL i

Answer 1

For my use case there were cookies and other issues that made the other approaches here unsuitable.

I ended up using an XMLHttpRequest to populate a FileReader (from How to convert image into base64 string using javascript, and then calling that using Selenium's ExecuteAsyncScript (as shown in Selenium and asynchronous JavaScript calls). This allowed me to get a Data URL which was straight forward to parse.

Here's my C# code for getting the Data URL:

public string ImageUrlToDataUrl(IWebDriver driver, string imageUrl)
{
  var js = new StringBuilder();
  js.AppendLine("var done = arguments[0];"); // The callback from ExecuteAsyncScript
  js.AppendLine(@"
    function toDataURL(url, callback) {
      var xhr = new XMLHttpRequest();
      xhr.onload = function() {
        var reader = new FileReader();
        reader.onloadend = function() {
          callback(reader.result);
        }
        reader.readAsDataURL(xhr.response);
      };
      xhr.open('GET', url);
      xhr.responseType = 'blob';
      xhr.send();
    }"); // XMLHttpRequest -> FileReader -> DataURL conversion
  js.AppendLine("toDataURL('" + imageUrl + "', done);"); // Invoke the function

  var executor = (IJavaScriptExecutor) driver;
  var dataUrl = executor.ExecuteAsyncScript(js.ToString()) as string;
  return dataUrl;
}