How to extract the MIME type from a base64 string.
・0 min read
Extract the MIME type from a base64 string using a regular expression.
function base64MimeType(encoded) {
var result = null;
if (typeof encoded !== 'string') {
return result;
}
var mime = encoded.match(/data:([a-zA-Z0-9]+\/[a-zA-Z0-9-.+]+).*,.*/);
if (mime && mime.length) {
result = mime[1];
}
return result;
}
Usage:
var encoded = 'data:image/png;base64,iVBORw0KGgoAA...5CYII=';
console.log(base64Mime(encoded)); // "image/png"
console.log(base64Mime('garbage')); // null
On github at miguelmota/base64mime