What "add page numbers to a PDF" actually means
You have a PDF. The PDF doesn't have page numbers, or it has them in the wrong place, or it's a section pulled from a longer document and the numbering needs to restart. You want a number stamped on every page — clean, readable, in the right corner — and you want it to take less than a minute.
That's the whole job. It sounds trivial, and it is trivial, which is why it's strange that the most-Googled tools for it ask you to upload your file to a server, wait in a queue, and then download the result. iLovePDF, SmallPDF, PDF24, Sejda — they all do the same dance. Your PDF leaves your machine, sits on someone else's disk for some number of minutes or hours, and comes back stamped. For a payroll register, a signed NDA, or a contract draft, that's a strange tradeoff to make for thirty seconds of convenience.
The Microapp Add Page Numbers to PDF tool runs the entire operation in your browser using pdf-lib. The file never moves. There's no upload progress bar because there's nothing to upload. Open your network tab while it works and you'll see zero outbound requests. The output PDF is built in memory and offered to you as a download.
How to use Add Page Numbers to PDF
The tool is one screen. Drop a PDF into the page, pick where the number goes and what format you want, click the button, save the result.
- Drag a PDF onto the drop zone, or click to pick one. File-size cap is 100 MB.
- Pick a position. Six options on a grid: top-left, top-center, top-right, bottom-left, bottom-center, bottom-right. Each one sits about 0.4 inch off the edge so it clears typical printer bleed margins.
- Pick a format. Four presets:
1(just the number),Page 1,1 / 10,Page 1 of 10. - Set a start number if you don't want the first stamped page to read "1." Default is 1; useful values are 17 (chapter starts mid-book) or 0 (front matter doesn't get counted).
- Click Add page numbers. The output file is named after the original —
contract.pdfbecomescontract-numbered.pdf— and lands in your downloads folder.
The result is rendered in Helvetica 11pt dark grey. That's a deliberate choice — see the section on defaults below.
Positions, formats, and what to actually pick
Most documents land on one of two configurations. Books, reports, and most printed material go with bottom-center, "Page 1 of 10". Legal documents, manuscripts, and academic submissions go with top-right, just the number. Everything else is a corner case.
| Position | When to use it |
|---|---|
| Bottom-center | The default for books, reports, brochures, internal documents. Reads naturally when flipping pages; doesn't fight with running headers. |
| Top-right | Standard for legal documents, court filings, academic manuscripts. Also useful when the bottom of the page has a fixed footer or signature block. |
| Top-center | Useful when there's a long footer (legal disclaimers, addresses) you don't want to overlap. |
| Bottom-right | Common in two-sided printed books — odd pages get bottom-right, even pages bottom-left. This tool numbers every page the same; for mirrored numbering you'd need a layout tool. |
| Top-left / Bottom-left | Rare. Specific layouts or non-Western reading orders. |
On format: pick what reads well at the size of the document. For a 6-page proposal, "Page 1" is friendlier than "1 / 6." For a 240-page report, "Page 1 of 240" can feel heavy in the footer — just the number, or "1 / 240," is cleaner.
If you can't decide, pick bottom-center, Page 1 of N, start at 1. That's what every word processor defaults to and it's right about 80% of the time.
A worked example: numbering a chapter that starts on page 17
You've extracted Chapter 3 of a longer book — pages 17 through 42 of the source document — and saved it as a 26-page PDF. The chapter's internal references talk about "page 23, table 4" and so on. If you number this PDF starting at 1, every reference is off by 16. You want the numbering to start at 17.
In the tool:
- Position: bottom-center
- Format: Page 1 of 10
- Start number: 17
Click Add page numbers. The first page of your PDF gets stamped Page 17 of 42, the second Page 18 of 42, and so on through Page 42 of 42. The "of N" total reflects the offset — 17 + 26 - 1 = 42, the position of the last page in the original numbering. The references inside the chapter line up. Total time, including the drop and download: under fifteen seconds.
Why there's no font, color, or size picker
This part is a deliberate choice and worth saying out loud. We could ship a font picker, a color picker, and a size slider. Sejda does. PDF24 does. The reason we don't is that those three controls add three decisions to a task that should take one decision.
Helvetica 11pt dark grey works on every PDF we've tested it against — white backgrounds, off-white book stock simulations, colored covers, scanned forms with mixed contrast. It reads as a page number and gets out of the way. The handful of cases where it doesn't work (a glossy black cover page where you'd want light type) are the same cases where you'd want to design the numbering as part of the layout, not stamp it after the fact.
If you genuinely need different typography — your company has a serif house font and the report needs to match — you're probably better served by adding numbers in the source document (Word, Pages, InDesign) and re-exporting. This tool is for the moment when you have a PDF in hand and just need numbers on it. Pick this for that case; pick the source-document path for everything else.
Page Numbers vs Add Header & Footer — which one to pick
The Add Header & Footer to PDF tool can also stamp page numbers — it has {page} and {total} tokens, so a footer like "Page {page} of {total}" produces the same output as our "Page 1 of 10" format here. So why two tools?
| Add Page Numbers | Add Header & Footer | |
|---|---|---|
| Best for | Just a number, one of six positions, four format presets | Richer text — company name, document title, draft markers, dates |
| Inputs | Position, format, start number | Two free-text fields (header and footer), alignment, tokens |
| Speed to use | Three clicks | Type two lines, pick alignment, click |
| Output | One text element, one corner | Up to two text elements per page (top + bottom) |
Pick Add Page Numbers when numbers are all you need. Pick Add Header & Footer when you want something like "ACME Corp - Confidential" at the top and "Page 7 of 12 | Draft 2026-05" at the bottom. Both tools are the same engine underneath; the UIs are different because the jobs are different.
What the tool does not change
pdf-lib adds a single text drawing to each page. It doesn't re-render the page, doesn't re-encode images, doesn't touch the document outline, doesn't rewrite metadata. That means:
- Bookmarks and table-of-contents links survive intact.
- Hyperlinks in the body of the PDF still work.
- Form fields remain fillable.
- Digital signatures on the PDF will be invalidated, because any modification to a signed PDF breaks the signature. This is true of every tool that modifies a signed PDF; it's not unique to ours.
- File size grows by a tiny amount per page — usually under 1 KB for the page-number text plus the embedded Helvetica font.
If you need to do something more invasive — rotate pages, delete a few, reorder — combine this tool with Rotate PDF, Delete PDF Pages, or Reorder PDF Pages in any order. Each tool runs the same way: in your browser, no upload, no queue.
Frequently asked questions
Where on the page does the number go?
One of six positions: the four corners plus top-center and bottom-center. Each sits about 0.4 inch off the page edge to clear typical printer bleed. Bottom-center is the most common pick for books and reports; top-right is the standard for legal documents.
What if my PDF already has page numbers?
The tool draws a new number on top of whatever is there — it doesn't remove the existing ones. If the position you pick collides with the built-in numbers, you'll get overlapping text. Either pick a different position, or remove the existing numbers at the source by re-exporting the original document without them.
Can I number only some pages, not all?
Not in v1. Every page gets a number. To skip a title page and table of contents, the trick is to Split PDF off the front matter, number the body separately, then merge them back together.
Will this work on a 500-page PDF?
If it's under 100 MB, yes. pdf-lib doesn't re-render pages — it just adds a text element — so the operation is fast. A 200-page PDF numbers in under a second. The 100 MB cap is about browser memory, not page count.
Is my PDF really not uploaded anywhere?
Correct. Open your browser's network tab before clicking the button. You'll see zero outbound requests during the stamp. The PDF bytes go from your file system to the browser's memory to the output download — never to a server. There is no server in this flow.
Does it work on password-protected PDFs?
No. pdf-lib refuses to open encrypted PDFs. Remove the password first in Adobe Acrobat or macOS Preview, then bring it here.
Why no font or color picker?
Because Helvetica 11pt dark grey looks right on almost every document and three extra controls would slow the tool down without making the output meaningfully better in the common case. If you have a documented need for branded typography on stamped numbers, the right path is to add numbers in your source document, not in a post-processing step.