[tempz]

Originally Posted by VIPStephan

I’m not so sure about that. I think you can display an image in a browser even without a file extension, as long as the MIME type is correct.

But anyway, britannic: Why don’t you just try it? Save an image without extension and load it in different browsers and you know it.

Oh yes, I forgot that.

Originally Posted by http://stackoverflow.com/a/5110460

The file extension isn't used for anything, really. The browser is checking for the Content-type header, which should be something like image/jpeg or whatever type of image you're serving.

This is used pretty often in sites which dynamically serve images, often from a database. I've seen plenty of image URLs like image.aspx?id=37 which, while it technically has an "extension" doesn't really mean that it's an image. It's all in the HTTP header values.