add page numbers to pdf header or footer

Footer placement, usually centered or in a bottom corner, is the most common convention for general documents like reports, letters, and everyday business files. It's a familiar, expected location that readers instinctively check without needing to think about it.

Header placement is more common for formal or academic documents where the footer is already reserved for citations, footnotes, or copyright text, and adding page numbers there would create visual clutter. Placing numbers in the header instead keeps the footer clean for its existing content.

Alignment adds another layer of choice: left-aligned numbers work well when a document is bound on the right, center alignment is the safest default for most documents, and right alignment suits documents where other header or footer content sits on the left, like a document title or author name.

If your document already has other header or footer content, like a logo, title, or date, check the final result carefully to make sure the page number doesn't overlap or crowd that existing content. Choosing an alignment on the opposite side of existing content usually avoids this problem cleanly.