What Add Page Numbers does
This tool stamps a page number onto every page of a PDF. You choose where the number sits (six positions: top or bottom, left, centre or right), the font size, and the number to start from. The numbers are drawn as real text in a standard font, so they print crisply at any size and are found by search. Everything else on the page is untouched, and the work is done in your browser without uploading the file.
Options
| Option | Choices | Notes |
|---|---|---|
| Position | Bottom/top × left/centre/right | Bottom centre is the convention for reports; bottom right for legal and academic documents |
| Font size | Any, default 12 pt | 10–12 pt suits A4/Letter; use 8–9 pt for slides or landscape pages |
| Start number | Any integer, default 1 | Set to 3 if the file is a chapter that follows two pages elsewhere, or 0 for an unnumbered cover |
Numbers are placed at a fixed inset from the page edge — roughly 30 pt (about 1 cm) from the bottom or top and 40 pt from the side — which keeps them inside the printable area of nearly all printers.
Choosing a start number
Documents often have front matter that should not be numbered, or are assembled from parts. A few patterns:
- Skip the cover: extract pages 2 to the end, number them starting at 1, then merge the cover back in front.
- Continue from another file: if part one ends on page 24, number part two starting at 25.
- Match printed numbers: if the original document's numbering started on its third page, start at −1 is not possible; instead extract from the third page and number from 1.
Common uses
- Scanned documents that arrived without numbers and need to be referenced in a meeting or court filing.
- Merged files — combining several PDFs produces a document where each part restarts its own numbering; stamping fresh numbers gives one clean sequence.
- Exports that lost their footer — some tools drop headers and footers on conversion.
- Handouts and slide decks where the audience needs to say “page 7” rather than describe a slide.
- Bates-style numbering for simple legal bundles — for full Bates labels with prefixes, use a dedicated legal tool.
Tips and limitations
- The number is drawn on top of existing content. If the chosen corner already has text, pick a different position — the tool does not detect overlaps.
- Pages of mixed sizes are handled individually: the inset is measured from each page's own edges.
- Rotated pages: the number follows the page's displayed orientation, so a landscape page rotated for viewing still gets its number along the bottom as you see it.
- Format is a plain number. “Page 3 of 12” or roman numerals are not supported here.
- Numbers cannot be removed afterwards without editing the PDF, so keep the original file.
- Encrypted PDFs must be unlocked before numbering.
Why numbers are added as text, not images
The tool uses pdf-lib to embed a standard font (Helvetica) and write the digits into each page's content stream. Text drawn this way scales with the page, stays sharp when printed at 600 dpi, adds only a few bytes per page, and is picked up by search and screen readers. Stamping an image of a number would bloat the file and blur on print.