Free browser tool
Add Stamp or Watermark to PDF
Overlay text like CONFIDENTIAL or an image such as a company seal on chosen pages — in your browser.
Drop a PDF here
or click to choose — stamping runs on your device
100% client-side — your PDFs never leave this device. Large PDFs use more memory — very big files may be slow or fail on phones.
About this PDF stamp tool
Mark drafts as CONFIDENTIAL, add a DRAFT watermark across every page, or place a company seal in the bottom-right corner of the last page.
Choose text or an image, then set position, size, opacity, rotation, and which pages to stamp. pdf-lib draws the stamp into the PDF locally.
A visual stamp is not a digital signature — it doesn't prove authenticity. For legally binding signatures, use a certified e-signature service.
Why stamp here
No upload, ever
pdf-lib runs inside your browser tab. Contracts, invoices, and IDs never touch a server.
Free, no signup
No account, no watermark added by us, no daily limit.
Works on mobile
Responsive layout for phone, tablet, and desktop — no app install.
Part of a PDF toolkit
Jump to merge, split, compress, delete, insert, or stamp — each with its own page.
How to stamp a PDF
- 1
Choose your PDF
Drop or select the PDF to mark.
- 2
Design the stamp
Type text or add a seal image; adjust position, opacity, rotation, and pages.
- 3
Apply and download
Click Apply stamp and save the stamped PDF.
FAQ
More from Okay OK
Okay OK is the official home of the OK product family — OK Tools, OK Video, OK Images, and more.
Visit okayok.ai