Add Page Numbers to PDF

This tool exists because court filings, academic submissions, and basically every corporate style guide want page numbers a specific way — and getting it exactly right (skip the cover page, restart at 1 for the main body, mirror margins for double-sided printing) is fussier than it sounds if you're doing it by hand in a word processor after the PDF already exists.

How it works

pdf-lib draws the number as a new text object directly onto each page, at whatever position and style you set — it's not editing anything that was already on the page, just adding a layer on top. That means the original content is untouched underneath, and if a page already had something printed in that corner (a header, a stamp), you can end up with visual overlap. The live preview exists specifically so you catch that before downloading rather than after.

Because it's a fresh text object rather than a form field, once you download the file the numbers are permanent — there's no "page numbering" setting to toggle off later in a different PDF viewer. If you think you might want to change the format later, keep your original unnumbered file around.

A real example

A 40-page academic report: pages 1-2 are the title page and table of contents (no numbers wanted), and the body should read "Page 1 of 38" starting on page 3, bottom-center. Set the page range to start from page 3, enable "restart numbering at this page," set the suffix to " of 38," and skip the first two pages entirely. The output shows nothing on pages 1-2 and clean "Page 1 of 38" through "Page 38 of 38" on the rest — without you having to manually calculate what number goes on which physical page.

Common mistakes

• Forgetting that "skip first page" and "start numbering at 2" are different things. Skip-first-page hides the number on page 1 but still counts it — so page 2 shows "2," not "1." If you want the visible content to start counting from 1, you need to restart numbering at that page, not just skip the display on the page before it. This is the single most common thing people email me about.
• Setting mirror margins without actually intending to print double-sided. Mirror margins alternate the number position left/right by page — great for a bound book, confusing and asymmetric-looking for a document that's only ever read on screen.
• Picking a font size that's fine on screen but tiny when printed. 8pt reads okay in the browser preview at 100% zoom; on a physical printed page it can be nearly invisible, especially in a light color. If the document is headed for print, preview at actual size or bump the size up a couple points.