What this does

This puts page numbers on a PDF — in any of nine positions, in Arabic or Roman numerals or letters, saying whatever you want them to say. The file is edited in your browser and never uploaded.

The distinction most tools miss

Which pages get a number is not the same question as what number they get.Leaving a cover unnumbered is completely normal, and the page after the cover is then pageone — not page two. Tools that treat the two as one setting produce a document that is off by one from the first page to the last, which is the single most common thing wrong with a numbered PDF.

So they are two boxes here. Pages to number decides which sheets get a stamp; put 2- in it and the cover is left alone. First number decides what the first stamped page shows. Leave it at 1 and the page after the cover reads “1”. Set it to 47 and the numbering carries on from a document that ended at 46.

{total} follows the same logic: it is the last number in the run, not the number of sheets in the file. A twenty-page document with an unnumbered cover reads “1 of 19”, because that is how many numbered pages there are.

Printing double-sided

A page number belongs on the outer edge, and on a double-sided document the outer edge changes with every leaf: right on the odd pages, left on the even ones. Number a booklet “bottom right” all the way through and half the numbers end up in the gutter, next to the staples.

Put it on the outer edge swaps the side on alternate pages. It does nothing to a number that sits in the middle of the foot, because a centred number has no side to swap.

How to use it

Drop in a PDF.
Pick what the number should say and where it goes.
If there's a cover, put 2- in Pages to number.
Step through the preview to check, then add the numbers and download.

Things worth knowing

Numbers go over the content, always. A watermark underneath the text is a choice; a page number underneath it is a page number nobody can read.
Nothing checks what's already there. If a page has its own number printed on it, you'll get two. Numbering is added, not reconciled.
Pages already turned are handled. A sheet saved sideways carries a rotation flag, and a number placed against the numbers in the file rather than the page you see would land on the wrong edge. This works against the page as displayed.
Latin letters, digits and ordinary punctuation only. The fonts built into PDF are WinAnsi-encoded, which covers those and no more. You'll be told which characters are a problem rather than handed a broken file.
Everything else in the file is left alone. Pages are edited in place rather than copied into a new document, so bookmarks, links, form fields and metadata survive.

Frequently asked questions

Is my file uploaded?

No. It's read and edited in your browser. You can watch the network panel while it runs, or disconnect from the internet once the page has loaded and number a PDF anyway — it still works.

How do I leave the cover unnumbered?

Put 2- in Pages to number. The cover is skipped and the next page reads “1”. If you'd rather it read “2”, set First number to 2.

Can I use Roman numerals for the front matter?

Yes, for a run of pages: set Pages to number to the front matter and choose Roman numerals, download, then run the result through again for the body in Arabic. Two passes, because one document can only have one numbering scheme at a time here.

Can I remove page numbers with this?

No. This adds them. Numbers already printed into a PDF are part of the page and can't be pulled back out.