Add Page Numbers to PDF

How do I add page numbers to a PDF?

1. Drop one or more PDFs onto the drop zone, or click it to choose them.
2. Under Position, choose Bottom centre, Bottom right, Bottom left, Top centre, Top right or Top left.
3. Under Format, choose 1, 2, 3 or 1 of 12 or Page 1, and set Start at if the numbering should not begin at 1.
4. Adjust Font size in points and Margin from edge in millimetres if the defaults of 11 pt and 12 mm do not suit.
5. Click Add page numbers.
6. Download the numbered PDF, or click Download all as ZIP if you numbered several files.

Add Page Numbers opens the PDF with pdf-lib in your browser and draws a short text label onto every page using Helvetica, one of the standard fonts every PDF viewer has built in, so no font needs to be embedded and the file grows by only a few kilobytes. The existing content is not touched or re-rendered; the number is an extra piece of text placed on top, which means it is selectable and searchable like the rest of the document. The label is positioned relative to each page's own size, so mixed A4 and landscape pages all get their number in the same corner.

Position and format are the choices that matter. Bottom centre is the convention for reports and essays; bottom right or top right suits documents that will be bound on the left, because the number stays visible when you flick through. The 1 of 12 format is useful for anything that may be printed and separated, such as a contract or a bundle for court, since a missing page is obvious. Page 1 reads more naturally in letters and manuals. Set Start at to something other than 1 when you are numbering a chapter that follows other material, for example starting at 23 so the numbers continue from a previous file.

Font size runs from 6 to 36 pt; 11 pt matches typical body text and 9 pt is discreet. Margin from edge, 4 to 40 mm, controls how far the number sits from the page edge; 12 mm clears the unprintable border on most printers, and 15 mm or more is safer for documents that will be bound. The tool cannot skip a cover page or number only a range, so if the first page must stay unnumbered, split it off with Split PDF, number the rest and merge again.

Several PDFs can be numbered in one go with the same settings and come back as a ZIP. There is no file size limit beyond device memory, no signup and no watermark. Everything runs on your device with open-source pdf-lib; the PDF is never uploaded and nothing is stored.

How it works: this tool uses pdf-lib and PDF.js (Mozilla), open-source libraries loaded into your browser. No server is involved, so Kilnfile never sees your file. Last reviewed 20 September 2026.

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