Add Page Numbers to PDF

Number a PDF's pages without uploading it

The usual way to paginate a merged contract pack or an exported report is to feed it to a page-number site that uploads your document to its server, stamps it there, and often gates the download behind a sign-up. For exactly the kind of file people paginate — contract exhibits, board packs, theses — that is backwards. This tool does the same job with zero upload: the numbering runs in your browser through pdf-lib, a pinned MIT library served from this page. Your file is read locally, each number is drawn onto its page in memory, and the numbered PDF is handed straight back as a download.

Four positions, three formats, computed per page

Pick where the number sits — bottom-center (the classic book position), bottom-left, bottom-right, or top-right (common on legal exhibits and reports) — and how it reads: bare 3, Page 3, or Page 3 of 12. The margin control is in PDF points, the unit PDFs actually use: 72 pt = 1 inch, so the default 36 pt keeps the number half an inch from the edges. A worked example: on an A4 portrait page (595.28 × 841.89 pt), an 11 pt bottom-center number 15 pt wide is drawn with its baseline at (290.14, 36); flip that page to landscape and the math re-runs with the sides swapped, so mixed-orientation files come out right. Top placements inset the top of the glyphs — not the invisible baseline — by the margin, so a corner number sits visually equidistant from both edges.

Start-at: the front-matter offset

Documents rarely number every physical sheet. A thesis whose cover and table of contents occupy the first two physical pages typically starts its visible numbering at 3 — set start numbering at to 3 and physical page 1 is labeled 3, page 2 is labeled 4, and so on down the file. Combine it with a range like 3-end to leave the front matter itself unstamped. In the Page 1 of N format, N is the last label actually used (start-at + page count − 1), so a 10-page file starting at 3 ends on Page 12 of 12 — never the off-by-front-matter Page 12 of 10.

Only the pages you choose

Leave the page field empty (or type all) to number everything, or use the same range syntax as the Split PDF and Watermark PDF tools — literally the same parser, shared between the three pages, so the rules never drift: 2-end on a 10-page file skips the cover, 1-3, 7 numbers four pages, and end always means the last page. Pages outside the range are left completely untouched — not renumbered, not shifted. Bad input is refused with a specific error — 12 on a 10-page file is out of range, 5-2 is reversed — never silently "fixed" into stamping the wrong pages.

Honest limits: added on top, Western digits only

Two things this v1 does not claim. First, the numbers are drawn on top of the existing page content — the tool cannot detect or remove numbers your PDF already has, so renumbering an already-numbered file produces two sets of numbers unless you pick a different corner. Second, labels are set in the built-in Helvetica font, which covers Western (WinAnsi) characters — fine for 1, Page 1 of 12 and every Latin-script variant, but this v1 offers no Roman numerals (i, ii, iii) for front matter and no Arabic-Indic or CJK numeral forms. The existing pages are not re-encoded: text stays selectable, vectors stay sharp, images keep their original bytes; each number adds a small text object, typically a few kilobytes across the whole file. Everything rebuilds live on every change — nudge the margin from 36 to 48 and the preview and the downloadable file both update; there is no Apply button to hunt for.