docx-js/docs/usage/packers.md

Packers

Packers are the way in which docx turns your code into .docx format. It is completely decoupled from the docx.Document.

Packers works in both a node and browser environment (Angular etc). Now, the packer returns a Buffer, Blob or base64 string. It is up to you to take that and persist it with node's fs, send it down as a downloadable file, or anything else you wish. As of version 4+, this library will not have options to export to PDF.

Export as Buffer

This will return a NodeJS Buffer. If this is used in the browser, it will return a UInt8Array instead.

Packer.toBuffer(doc).then((buffer) => {
    fs.writeFileSync("My Document.docx", buffer);
});

Export as a base64 string

Packer.toBase64String(doc).then((string) => {
    console.log(string);
});

Export as Blob

This is useful if you want to send it as an downloadable in a browser environment.

Packer.toBlob(doc).then((blob) => {
    // saveAs from FileSaver will download the file
    saveAs(blob, "example.docx");
});