You finished the document and now the recipient just says "send me the file." The single biggest mistake here is sending a Word .docx when they needed a fixed layout, or a PDF when they needed to edit. The choice is not about the software you used — it's about who controls the file next.
Use a PDF when the goal is that the file looks exactly the same everywhere. Contracts, invoices, resumes, forms, and anything that will be printed or signed should be PDF. The layout, fonts, and page breaks are locked, so the other person sees what you see. If you need to combine several documents into one clean packet, the PDF Merge tool stacks them in order, in your browser, with nothing uploaded. If one section is too heavy to email, the PDF Compress tool does a safe, lossless re-save.
Use a DOCX (Word) when the other person has to edit the words. Drafts, templates, content someone else will rewrite, and collaborative working files belong in .docx. The risk with PDF is that it's painful to edit; the risk with DOCX is that your careful formatting can shift the moment they open it in a different version of Word or a different app.
A simple rule: "Will they change it?" → DOCX. "Must it look identical?" → PDF. When you only need one page or one figure out of a PDF to paste into a doc, the PDF to Images tool renders that page to a PNG locally, so you drop a clean picture into the Word file instead of fighting with copy-paste.
Quick path: decide edit-vs-lock, export to the matching format, and if you're sending PDFs, merge or compress them first so the recipient gets one tidy, openable file. Everything here runs in your browser — the document never leaves your device.