Answer by Gentle153 for PHP- Get file type by URL

You are not going wrong anywhere. exif_imagetype returns the value of one of the image type constants: http://php.net/manual/en/image.constants.php

If you would like to convert this to an extension string, you could use a switch statement:

$typeString = null;$typeInt = exif_imagetype($image_path);switch($typeInt) {  case IMG_GIF:    $typeString = 'image/gif';    break;  case IMG_JPG:    $typeString = 'image/jpg';    break;  case IMG_JPEG:    $typeString = 'image/jpeg';    break;  case IMG_PNG:    $typeString = 'image/png';    break;  case IMG_WBMP:    $typeString = 'image/wbmp';    break;  case IMG_XPM:    $typeString = 'image/xpm';    break;  default:     $typeString = 'unknown';}

You may want to change the order to most to least frequently expected for better performance.