Add a watermark and page numbers to PDF

Two jobs in one tool

The stamper adds things on top of every page without touching what is already there. A watermark is one large, faint line of text across the page, such as DRAFT, CONFIDENTIAL or COPY. Headers and footers are small lines at the top and bottom, most often page numbers, but also a document title, a date or a file name. You can use either, or both at once. The preview shows the first page with your settings as you change them.

Watermarks that work

A watermark has to be visible without getting in the way of reading. The default, red text at 18 percent opacity turned 45 degrees, stays readable under the text of most documents. A few adjustments cover most needs:

• Size: around 60 points spans an A4 or Letter page diagonally for a single word; longer phrases need less.
• Opacity: 10 to 25 percent for documents people must read, more for previews you do not want used.
• Repeat across the page tiles the text, which is harder to cut out of a screenshot.
• Colour: grey looks neutral; red signals a status such as draft or confidential.

A watermark added this way is a separate layer on the page. It shows on screen and in print, but someone with a PDF editor can remove it, as with any added layer. For documents that must not be reused, combine it with a password from protect PDF that blocks editing, or share a flattened copy made with compress PDF set to Flatten pages.

Headers, footers and page numbers

Each of the six slots, left, centre and right at the top and bottom, takes any text plus four tokens that are filled in per page: {n} for the page number, {total} for the number of pages, {date} for today's date and {filename} for the file name. One click sets common page number styles such as Page 1 of 9, 1, - 1 - or 1 / 9.

• Start numbering at continues a sequence, for a document that follows another one.
• Skip the first page leaves a cover page clean and starts the visible numbers on page 2.
• Only these pages limits the stamp to ranges such as 2-10.
• Text size and distance from the edge keep the numbers clear of the page content; 28 points from the edge suits most documents.

Text in any language

Text in Western European languages is written into the PDF as real text, in the standard Helvetica font every PDF reader has. Text the standard fonts cannot hold, such as Arabic, Greek, Chinese or emoji, is drawn as a sharp picture at three times the size instead, so it looks right in any reader without embedding a large font.

If something goes wrong

• The watermark hides the text. Lower the opacity, or choose grey.
• Numbers overlap the page content. Raise the distance from the edge or lower the text size.
• It says the PDF is password protected. Unlock it first with unlock PDF, if you have the right to.
• Page numbers should skip some pages. Use Only these pages, or stamp the parts separately after splitting with split PDF.