Adding page numbers to a PDF makes it easier to navigate, reference sections in conversation, and print with a predictable reading order. Many documents arrive unnumbered — scanned books, merged reports, combined documents — and adding numbers before sharing or printing takes seconds.
Placement options
Page numbers are typically placed in one of six positions: bottom center, bottom left, bottom right, top center, top left, or top right. Bottom center is the conventional choice for most documents; bottom right is standard for legal briefs and academic papers where the right margin is used for annotations.
Filum's Page Numbers tool lets you choose position, so the number lands where your document's layout expects it.
Starting number
By default, numbering starts at 1 on the first page of the file. If you are adding numbers to a document that is part of a larger work — a chapter extracted from a book, an appendix that continues a report — you can set the starting number to match the document's intended position.
On-device processing
The Page Numbers tool runs entirely in your browser. The PDF is loaded locally, the numbers are stamped using pdf-lib, and the output is downloaded to your device. Nothing is uploaded. This makes it safe to use on confidential documents: legal filings, financial reports, medical records.
When page numbers matter
Page numbers are most important when the document will be read non-linearly: reports that reference specific pages, technical documents with a table of contents, legal filings where page citations are required, and any document long enough that readers need navigation cues. Adding page numbers transforms a continuous PDF into a citable, navigable document.
Position and format options
Page numbers can be placed at the top or bottom of the page, and aligned left, center, or right. The most common placement is bottom-center for documents and top-right for formal reports. The Filum Page Numbers tool lets you choose position and whether to show the total page count (e.g. "Page 3 of 10" vs just "3").
Page numbers are stamped as text elements in the PDF — they remain selectable and searchable, not rasterised. The font matches the document's baseline rendering size so the number is legible at standard zoom without being intrusive.
On-device processing
Page numbering runs entirely in your browser using pdf-lib. The document is never uploaded. For confidential documents, briefs, or reports, this means the content stays on your machine throughout the operation.