Add Page Numbers to PDF

Why page numbers matter

Page numbers are what make a long document usable. They let a reader jump to a reference, a printer collate a stack correctly, a lawyer cite an exhibit and a teacher tell a class where to look. Word processors add them automatically, but the moment a document becomes a PDF — a scan, an export, a merge of several files — the numbering is gone or wrong. If the pages are not in the right order yet, fix that first in the PDF Page Organizer, then number the result. This tool puts it back on any PDF, whatever produced it.

Formats you can use

Plain digits are the default, but a front matter section usually wants lower-case roman numerals, a report often reads better as "Page 3 of 24", printed handouts like the classic "- 3 -", and legal or tender documents frequently need a prefix such as ABC-001. The custom pattern covers all of that: type anything and use {n} where the number goes and {total} for the final number.

Skip the cover, start at any number

Two separate settings keep this flexible. Pages to number decides which sheets get a stamp — leave it blank for every page, or type 2- to skip a cover, 3-20 for a section, or 2,4,6 for specific sheets. Start at decides what the first stamped page reads. Skipping a cover and starting at 1 gives you the usual "cover unnumbered, body starts at 1" layout; starting at 47 continues the numbering of a document that came before it.

Mirrored margins for double-sided printing

In a printed book the page number sits on the outer edge of the sheet, which means it swaps sides between left-hand and right-hand pages. Tick Mirror margins and a left or right position flips automatically on alternating pages, so a bound or stapled document looks right. For centred numbers the setting makes no difference.

Rotated and landscape pages

A PDF page carries a rotation flag that viewers apply when displaying it, which is why naive numbering tools sometimes print sideways numbers on scanned documents. This tool reads that flag for every page and places each number in the page's own visual space, so the digits read upright and sit in the corner you actually see — even in a file that mixes portrait and landscape sheets.

Choosing a margin that survives printing

Two things eat into a page number after you export it. A home or office printer keeps an unprintable border, typically 4–6 mm, so a number set 5 mm from the edge can be clipped on paper even though it looks fine on screen. Binding takes more: a stapled corner needs about 10 mm of clearance, a spiral or comb binding 15–20 mm on the bound edge. The defaults here — 15 mm from the side, 12 mm from the top or bottom edge — sit safely inside both. If the document will be bound, turn on mirrored margins so the number always lands on the outer edge, away from the spine.

Numbering a document that will be printed double-sided

For a double-sided document the odd-numbered pages are the right-hand sheets and the even ones are the left. That is the whole reason mirrored margins exist: a number pinned to the bottom right would sit near the spine on every left-hand page. Tick the option and a left or right position flips automatically, exactly the way a printed book does it. Centred numbers need no flipping. If you also plan to print two pages per sheet, add the numbers first — the numbers are drawn into each page, so they scale down with it.

Privacy & security

The PDF is opened, stamped and re-saved with JavaScript inside your browser. No copy is uploaded, nothing is stored on a server, and the page keeps nothing once you close the tab. That matters for the documents that most often need numbering: contracts, court bundles, tender submissions, medical records and financial statements.

A note on quality

Numbers are drawn as real text using the PDF standard fonts, not as an image stamped over the page — unlike a watermark, which is meant to sit visibly on top of the content. They stay crisp at any zoom level, print sharply, and remain selectable and searchable in a PDF reader — and because the rest of the file is untouched, your original text and images keep their exact quality.