Add Page Numbers to PDF Online Free – Private, In Your Browser
Insert customizable page numbers into your PDF documents instantly inside your browser. No files are uploaded to any server, keeping your confidential legal, financial, and academic papers strictly private.
Drop a PDF file here to add page numbers
Click to browse, drag and drop, or paste from clipboard
Select any PDF document. Customize position, starting number, and format. Processed entirely in your browser.
Document Name
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How to use Add Page Numbers to PDF
- 1 Select or drop your PDF document into the dropzone.
- 2 Choose your preferred number position (Bottom Center, Bottom Right, Bottom Left, Top Center, Top Right, or Top Left).
- 3 Select your numbering format ("Page 1 of N", "1, 2, 3...", "Page 1", or "1 / N") and set your starting number.
- 4 Click Add Page Numbers & Download to stamp your document and download the finished file.
What it does — and what it doesn't
Your document is loaded in your browser via the @cantoo/pdf-lib engine (MIT license). Vector text coordinates are calculated dynamically based on page dimensions and Helvetica font metrics. The page numbers are stamped directly onto the document canvas in browser memory without rasterization or quality degradation, and the final document is exported directly to your computer.
Limits and browser boundaries
- Maximum recommended PDF file size: 100 MB.
- Encrypted or password-protected PDFs cannot be modified and prompt an informative error message.
- Supports standard 1-based and custom integer starting offsets.
Verified Test Lab Measurements
Real numbers recorded in automated browser testing (docs/test-results/add-page-numbers-to-pdf.json).
| Fixture / Scenario | Input Size | Output / Result | Duration |
|---|
Client-Side Privacy Proof
All computation executes strictly inside your device CPU and GPU memory. Your file bytes, photos, and document text are never uploaded or transmitted to any server.
Verify it yourself in 5 seconds:
- Press F12 (or right click → Inspect) and switch to the Network tab.
- Drop your file into the tool above and click process.
- Confirm that zero outbound requests or file payloads leave your computer.
Frequently asked questions
Is my PDF uploaded to any server or cloud service?
No. The entire numbering process executes locally in your browser tab. Zero bytes of document data or text are transmitted over the network.
Can I customize where the page numbers appear on each page?
Yes. You can position page numbers in six different locations: Bottom Center, Bottom Right, Bottom Left, Top Center, Top Right, or Top Left.
Can I choose different page numbering formats?
Yes. You can select between standard numeric ("1, 2, 3..."), "Page X", "Page X of N", and "X / N" styles. You can also specify any custom starting number.
Will adding page numbers reduce the quality of my document or text?
No. Page numbers are stamped as native vector text using embedded standard Helvetica fonts. Existing text, images, and vector formatting remain untouched.
What happens if my document is password-protected or encrypted?
Encrypted PDFs are detected upon loading and trigger a clear notification. For security, password encryption must be removed before page numbers can be added.
What were the verified processing speed and file size measurements in the test lab?
In our verified test lab, stamping page numbers onto a 4-page source PDF (981 bytes) in "Page X of Y" format produced a 2,407-byte document in just 24 milliseconds with zero network requests.