How to update an already fetched image?

Updating an image that was previously fetched and then updated via the original remote URL, can be done by either of the following:

1. Via the UI, by deleting the resource from the Media Library. It will be automatically invalidated on the CDN and the re-fetched when accessed once again.

2. Via the API, by calling the explicit method with the public ID (i.e., the remote image URL) and setting the invalidate flag to true, e.g. (Node.js):

   cloudinary.uploader.explicit(URL, { type: "fetch", invalidate: true }, function(result) {
           console.log(result)
   });

3. Via the API, by calling the destroy method with the public ID and setting invalidate: true. 

   cloudinary.v2.uploader.destroy(URL, { type: "fetch", invalidate: true }).then(callback);

Note that in both flows, the CDN may take few minutes to propagate the purge and bring up the new image.