PDF Page Numberer

Printed page numbers and PDF page positions often diverge. A cover can be the first page in the file but carry no visible number, front matter may use Roman numerals, and a report added to an earlier volume may need to begin at 47 rather than 1. A sound numbering plan separates the pages that receive marks from the sequence printed on them.

Visible numbering serves readers who cite, print, or assemble the document. It does not change the file's page order, create new pages, or necessarily change the page label shown by a PDF viewer. Those are separate parts of a PDF and can remain different after text numbers are stamped onto the page.

PDF page

The page's physical position in the file, counted from 1.

Sequence number

The value assigned to each selected page, beginning from a chosen starting value and increasing by one.

Label

The complete text drawn on the page, such as Page 7 of 18 or iv.

Anchor

The top or bottom placement, aligned to the left, center, or right of the page box.

Selective numbering is useful for covers, appendices, inserted sheets, and combined packets. Facing-page layouts add another choice because outside-edge labels normally alternate right on odd PDF pages and left on even PDF pages. Centered labels do not need that alternation.

A mathematically valid position can still cover existing footer text, sit too close to a crop boundary, or disappear against a dark background. Page size, rotation, font size, margins, color, and opacity all affect readability. Keep the original PDF and inspect the finished copy in a viewer before distributing or printing it.

How to Use This Tool:

Choose the page scope and numbering sequence first; appearance settings only refine where and how the finished labels are drawn.

1. Choose one unlocked PDF no larger than 75 MiB and containing no more than 500 pages. The sample PDF is available for a placement rehearsal.
2. Enter Pages to number as all, odd, even, comma-separated page numbers, an ascending range such as 3-7, or an open range such as 8-. An out-of-range or descending selection must be corrected before stamping.
3. Set the position, Label format, Start number, and numbering style. The label must contain {n}; optional tokens can add the selected-page total, original PDF page, or document page count.
4. Adjust the built-in font, size, color, opacity, and margins when the document needs them. Enable Mirror facing pages only for left- or right-aligned outside-edge numbering.
5. Add the numbers, compare the stamped count and first and last labels with the plan, then download and visually inspect the numbered PDF.

Interpreting Results:

The selected-page count confirms how many stamps were created, while the first and last labels confirm the sequence. The Stamp ledger ties every label to its original PDF page and calculated position. Check these values before relying on the placement chart, which summarizes distribution rather than showing page content.

• A six-page selection beginning at 10 ends at 15, regardless of the original PDF page numbers selected.
• {total} means the number of selected pages; {docTotal} means every page in the source document.
• Mirroring follows odd and even PDF page positions, not the printed sequence value.
• A successful save proves that a new PDF was created, not that every stamp avoids existing text. Open representative first, middle, last, rotated, and unusually sized pages.

Technical Details:

Page numbering is a deterministic transformation with three stages: parse the page selection, generate one label per selected page, then place each label inside that page's box. Duplicate selections collapse to one page and the final page list is sorted in ascending PDF order.

Transformation Core

Formula Core

For selected-page index i, beginning at zero, the sequence value is the start number plus that index.

Horizontal placement uses page width W, measured text width T, and horizontal margin M. The raw coordinate is chosen by alignment, then constrained so the label remains inside the page box.

For vertical margin V, page height H, and font size S, bottom labels use V as the baseline and top labels use H − V − S. Horizontal and vertical coordinates are finally clamped to the drawable page box.

Number and input boundaries

Privacy and Limits:

The PDF is read and stamped in the current browser tab; it is not uploaded for processing. Password-protected or otherwise unreadable files cannot be opened. The output is a separate copy, but numbering does not repair damaged PDFs, alter viewer navigation labels, detect existing headers or footers, or guarantee print-safe placement. Retain the original and inspect the result before replacing any production document.

Worked Examples: