Add a Stamp to a PDF
Upload a PDF and a seal image, then stamp across pages exactly where you see them. Turn on the perforation seal to auto-split it vertically by page count for a perfect fit. Everything is processed locally in your browser — files are never uploaded.
What is a perforation seal?
A perforation seal (also called a riding seal) is a way of stamping that protects the integrity of a multi-page document. It is applied across the seam between pages so that a single seal is divided onto adjacent pages — the impression is only complete when every page is lined up in order. If any page is swapped, added, removed or tampered with, the marks at the seam become misaligned or missing, guaranteeing the document's continuity and authenticity.
A short history
Stamping across seams is a long tradition. As early as China's Han dynasty, official documents were sealed across the join to prevent tampering; during the Tang and Song dynasties seam-stamping was widely used on contracts, household registers and official papers. Although watermarks, anti-counterfeit backgrounds and digital signatures have since appeared, the perforation seal remains intuitive and reliable, and still carries legal and evidentiary weight on contracts, receipts and formal documents today.
Types of perforation seal
Standard perforation seal
The most common form — the seal is stamped at the document seam to keep multiple pages continuous and complete.
Anti-counterfeit seal
Uses special ink or security patterns to make forgery harder; common on important contracts.
Electronic perforation seal
A digital seal backed by an encryption certificate that can be verified online — ideal for paperless work.
Custom perforation seal
Includes a company logo, serial number and other personalization, balancing recognizability and security.
Official / government seal
A legally effective official seal used on government and formal institutional documents.
Where perforation seals are used
Key steps for using a perforation seal correctly
- 1
Prepare the file
Organize the multi-page PDF you need to stamp and confirm page order and content are correct.
- 2
Choose the position
Pick the document seam (usually the right binding edge) so every page is covered.
- 3
Adjust the size
Choose a seal size that suits the page count so each slice stays legible.
- 4
Handle multiple pages
With the perforation seal on, the system auto-splits vertically by page count and reassembles into the full seal.
- 5
Keep compliant records
For formal use, follow your organization's stamping rules and retain stamping records and originals for reference.
Frequently asked questions
Does this online tool upload my PDF and seal?
No. PDF parsing, seal compositing, perforation-seal slicing and export all happen locally in your browser — files are never uploaded to any server. Private and secure.
How is the perforation seal split automatically?
When the perforation seal is on, the tool divides the seal image vertically into the same number of slices as the PDF's page count and fits each slice to the right seam of its page. Line all pages up in order and the seal is fully restored.
Can I stamp each page of a multi-page PDF separately?
Yes. Switch pages and stamp anywhere on each one — what you see is what you get. On export, the stamps from every page are written into the PDF.
What's the difference between watermarked and watermark-free export?
Watermarked export is free and overlays a light site watermark on each page. Upgrade to Pro to export a watermark-free stamped PDF, suitable for formal layout and delivery.
Does this stamp have legal effect?
This tool is mainly for document layout, proof previews and personal-use stamping effects. For legally effective electronic seals, please use a compliant electronic-signature and digital-certificate service.
Reminder: this tool is for document layout, proof previews and lawful personal use. For formal contracts and legally effective electronic seals, please use a compliant electronic-signature / digital-certificate service and follow the stamping rules of your organization and region.