Add Page Numbers to PDF

This tool writes page numbers onto a PDF and gives you a new file. It is for the everyday finishing job: numbering a contract or a report before sending it, putting "Page 3 of 12" on a scanned document whose pages were never numbered, stamping "1 of 4" on a form set, or adding a footer number to pages you assembled elsewhere. You choose the position, the wording, the starting number and the look, and the numbering is drawn only on the pages you pick.

There are six positions: top-left, top-center, top-right, bottom-left, bottom-center and bottom-right. The margin is the clearance from the page edge in points (1 point = 1/72 inch); 24 pt is about 8.5 mm. The position is worked out per page, so a document that mixes page sizes still has every number sitting neatly inside its own margins.

The label is a template. {n} is the page's number and {total} is the document's page count, so "Page {n} of {total}" prints "Page 3 of 12" on the third page of a twelve-page file. The four presets cover almost everything — 1, Page 1, 1 of N, Page 1 of N — and Custom lets you type your own template, for example "{n} / {total} — Confidential". The start number lets the first numbered page read something other than 1, which is useful when a document continues another one. {total} is always the page count of the whole PDF; if you set a start number above 1 the pair can look odd (for example "5 of 3" on a three-page file), so "of N" is best used with a start of 1. The font is one of the three built-in PDF fonts — Helvetica (sans-serif), Times (serif) or Courier (monospace) — and the size is 6–72 pt. Labels are drawn in black.

Pages can be the whole document or a list you type, such as "1-3, 5". A common use is numbering everything except a cover page: choose Selected pages and type 2-.

What "adding" means here: the number is drawn as ordinary text onto each page's content, so it is baked in — every reader and printer shows it, and it stays put. It is not an electronic page-number field (the PDF format has no such live field for page numbers), so a reader cannot toggle it on and off, and you cannot select it as a field the way you can a form box. Because the label is placed on top of the page, put the margin somewhere there is room: if your pages already have a footer or a page number from another program, choosing a different position or a larger margin avoids printing on top of it. The label is drawn with a standard font, which covers Latin letters, digits and punctuation but not Arabic, Chinese, Japanese, Cyrillic or emoji — a template using those characters is refused with a message saying so rather than producing blank boxes.

Two cautions. First, an encrypted or password-protected PDF cannot be edited here and is refused with a clear message; open it in a PDF reader with its password and save or print an unprotected copy, then number that. Second, changing a PDF invalidates a digital signature: if the file is signed, the signature covers its exact original bytes, so number the PDF before signing it, or accept that the signature will no longer validate in a signed copy.

Everything runs in your browser: the PDF is read, numbered and saved inside the tab, and is never uploaded. You can confirm in your browser's developer tools, on the Network tab, that no request carries your document. Files up to 200 MB are accepted, because the whole file is held in the tab's memory while it is edited.

1. The file's first bytes are checked for the PDF signature, then pdf-lib opens it; a damaged or encrypted file is refused with a specific message and the page count is read. 2. The settings are validated: a whole start number of 0 or more, a font size between 6 and 72 pt, a margin between 0 and 200 pt, and a label that contains {n}. 3. The pages to number are all pages, or the list you typed (numbers, ranges like 2-6, and 8- for page 8 to the end), checked against the page count. Pages are numbered in ascending order, so the first numbered page gets the start number and the next gets one more. 4. Each label is built by replacing {n} with the page's number and {total} with the document's page count. 5. The label is measured with the chosen font, and its baseline position is worked out from the anchor: left is the margin from the left edge, center is (page width − label width) ÷ 2, right is page width − label width − margin; bottom is the margin up from the bottom edge, and top is page height − margin − label height measured down from the top. PDF user space puts the origin at the bottom-left corner with y increasing upwards, and pdf-lib's drawText places the text baseline at (x, y), so the label height used here is the height above the baseline (the font's ascender at that size). 6. The label is drawn on each chosen page and the document is saved as <name>-numbered.pdf. Your original file is not changed.