need recomendation for form that has 300 fields

if you have 300 fields to complete in your application form. Do you prefer do it online (fill in the website(e-form), of course with save draft feature so you can come back later) or you just download a PDF from that website and you filled it offline on your computer, after that you upload the pdf to that website?

The forms itself for government application form, it has tax fields, company profile, investor profile etc.