Creating a BLOB from a Base64 string in JavaScript

Question

I have Base64-encoded binary data in a string:

const contentType = \'image/png\';
const b64Data = \'iVBORw0KGg         


        

Answer 1

For all copy-paste lovers out there like me, here is a cooked download function which works on Chrome, Firefox and Edge:

window.saveFile = function (bytesBase64, mimeType, fileName) {
var fileUrl = "data:" + mimeType + ";base64," + bytesBase64;
fetch(fileUrl)
    .then(response => response.blob())
    .then(blob => {
        var link = window.document.createElement("a");
        link.href = window.URL.createObjectURL(blob, { type: mimeType });
        link.download = fileName;
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);
    });
}