@Olivia_Benedetti I convert word documents to PDFs. That way if beta readers want to print it, they can't change the document first, at least not without purchasing adobe suite. You can also set your beta document up as a google doc that becomes unavailable at a certain point, so that the readers can't have the book forever. Unless of course, if they decide to print it. That's a lot of paper and ink though! There's a way to make google docs read only. I know you can just share without giving editing rights, so that would be perfect for beta reading too. I did a beta read and it was through google docs. If you send a PDF I don't know if there is a way to make the PDF expire like a google doc can.