Blob from DataURL?
User Matt has proposed the following code a year ago ( How to convert dataURL to file object in javascript? ) which might help you
EDIT: As some commenters reported, BlobBuilder has been deprecated some time ago. This is the updated code:
function dataURItoBlob(dataURI) { // convert base64 to raw binary data held in a string // doesn't handle URLEncoded DataURIs - see SO answer #6850276 for code that does this var byteString = atob(dataURI.split(',')[1]); // separate out the mime component var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0] // write the bytes of the string to an ArrayBuffer var ab = new ArrayBuffer(byteString.length); // create a view into the buffer var ia = new Uint8Array(ab); // set the bytes of the buffer to the correct values for (var i = 0; i < byteString.length; i++) { ia[i] = byteString.charCodeAt(i); } // write the ArrayBuffer to a blob, and you're done var blob = new Blob([ab], {type: mimeString}); return blob;}
Like @Adria method but with Fetch api and just smaller [caniuse?]
Don't have to think about mimetype since blob response type just works out of the box
Warning: Can violate the Content Security Policy (CSP)
...if you use that stuff
var url = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg=="fetch(url).then(res => res.blob()).then(blob => console.log(blob))
Don't think you could do it any smaller then this without using lib's
In modern browsers one can use the one liner suggested by Christian d'Heureuse in a comment:
const blob = await (await fetch(dataURI)).blob();