Is my document uploaded anywhere?
No. A .docx is a ZIP; it is opened in this browser tab, its text is read there, and the PDF is written there. Nothing is sent to a server, and there is no server to send it to.
Choose a .docx. Its headings, paragraphs, lists and tables are read on this device and typeset onto the page size you pick — as text you can select and search, not a picture of a page. Images and Word's exact layout are not carried over.
Result
pages
No. A .docx is a ZIP; it is opened in this browser tab, its text is read there, and the PDF is written there. Nothing is sent to a server, and there is no server to send it to.
Because it is set again rather than photographed. Word's layout depends on its own fonts, spacing and pagination, none of which exist here. What survives is the document's structure and every word of its text — selectable, searchable, and a few kilobytes instead of a few megabytes. When the exact look matters more than the text, print to PDF from Word.
They are left out. The text around them is kept in order, so nothing reads as though a sentence is missing, but the pictures are not carried over.
No. The old Word 97-2003 format is not a ZIP and shares almost nothing with .docx. Opening it in Word or LibreOffice and saving as .docx takes a moment and is the only reliable conversion.
Tracked changes appear as the document currently reads, and comments are dropped. If you need the markup itself, accept or reject the changes in Word first.