Javascript - get extension from base64 image

Question

I have a base64 encoded image returned from a service and it looks like this:

/9j/4AAQSkZJRgABAQEASABIAAD/4Yp2aHR0cDovL25zLmFkb2JlLmNvbS94YXAvMS4wLwA8P3hwYWN         


        

Answer 1

A bit late but it seem the question was misunderstood. He just only had the base64 content of the image, not the full data URI.

I wrote here for anyone who encounters with this quest, you can read the first character of content content.charAt(0). By base64 image content if the first char is:

'/' : jpg

'i' : png

'R' : gif

'U' : webp

So for your case, it is 'jpg'.