PDF Page Numbers

This tool stamps a plain Arabic page number on every page of a PDF. You choose whether it sits at the bottom centre, bottom right or top centre, set the number to start from, and download the processed copy. It is deliberately basic. It writes bare digits such as 5, and does not support formats like Page 5 or 5 / 20, Roman numerals, skipping the cover, or different positions for odd and even pages. It suits quickly numbering a PDF that has no page numbers, or numbering it from a chosen value because it will be inserted into a larger document.

How to use it

1. Click the dashed box that says Click to select a PDF file and choose the PDF to number.
2. Under Page number position, click Bottom center, Bottom right or Top center. Bottom center is the default.
3. In Starting page number, enter the number to show on the first page. The default is 1. If this file continues a larger document from page 5, enter 5.
4. Click Add Page Numbers & Download. The button reads Processing… while it works and stays disabled until a file is chosen.
5. Your browser downloads paginated.pdf. Open it and check that the numbers do not collide with existing content.

Where the numbers go

Each number is written in 11 point Helvetica in dark grey (about 30% grey). The position is computed from the page size. Bottom centre means horizontally centred and 24 points above the bottom edge. Bottom right means 36 points from the right edge and 24 points above the bottom. Top centre means horizontally centred and 36 points below the top edge. Page k shows the number start + k - 1. The coordinates below were computed with the same PDF library (pdf-lib) for a portrait A4 page of 595 by 842 points. The digit 5 is about 6.1 points wide, so centred its x position is about 294.44. The two-digit number 12 is about 12.2 points wide, giving x of about 291.38 and y of 24 at the bottom centre, x of about 546.77 at the bottom right, and y of 806 at the top centre. If a three-page file starts at 5, the pages receive 5, 6 and 7.

Limits and known quirks

• Only plain digits are written. You cannot add a prefix or suffix, or change the font, size or colour.
• There are three fixed positions. There is no bottom left, top left or top right option.
• Numbers go on every page. You cannot skip the cover or number only some pages, so having the body start at 1 while the cover stays unnumbered is not possible directly.
• The starting number can be 0, in which case the first page shows 0. An empty or unreadable field falls back to 1, and a negative number is changed to 0.
• For pages that carry a rotation value, which is common in scans, the position is calculated in the displayed orientation and the number is rotated with the page, so it appears where you see it on screen; it is still worth checking the download.
• The number is drawn over the existing content. If the page already has text or a footer in that area, they can overlap.
• Files with an open password and damaged files fail with: Processing failed. Please make sure the file isn't corrupted, or try again.

Can I leave the cover page out?

Not directly. The tool numbers every page. One workaround is to split the cover off with another PDF tool, number the body, and then merge the two again, since the cover would otherwise receive a number.

What if numbers are duplicated or misplaced?

If your file already has page numbers, adding more gives you two numbers on each page, because the tool does not detect existing ones. If the position is wrong, try a different option, for example top centre when your existing footer is at the bottom. Rotated pages get their numbers placed according to the displayed orientation.

Does it support Chinese numerals?

No. The tool uses the standard Helvetica font and writes Arabic digits only. This avoids embedding any extra font and keeps processing fast.

Does the file get larger?

Each page gains a small piece of text content, so there may be a slight increase in theory. We have not run a size comparison, so we do not promise a figure.

Privacy and processing

The PDF you choose is read and processed only in your browser by the bundled pdf-lib component, and the page contains no code that uploads it. The new file is downloaded straight to your device and no copy is kept. Your selections are cleared when you refresh or close the page.