How to get the image extension from a remote image url that doesn't contain image extension in the url

Question

I\'m trying to use the Image API to get the image data/extension for image urls.

I can easily use regex to the file extension from names like {domain}.com/path-to-im

Answer 1

You can use fetch(), Response.blob(), FileReader.prototype.readAsDataURL()

fetch("http://placekitten.com/g/1000/1000")
.then(response => response.blob())
.then(blob => {
  console.log(blob.type);
  let reader = new FileReader();
  reader.onload = () => {
    console.log(reader.result)
  }
  reader.readAsDataURL(blob) 
})