Add a stamp to a PDF online for free

How to add a stamp to a PDF online

The PDF editor and the stamp maker work as a pair. Create the stamp artwork once, then place it on as many PDFs as you need. The PDF editor itself is free and does not need an account.

1. Prepare the stamp. Design it in the stamp maker online and export a transparent PNG. A 3x PNG keeps the edges sharp when you resize the stamp on the page.
2. Open your PDF. Upload the document in the PDF workspace. Files are processed in your browser and cleared automatically about an hour after use.
3. Insert and position the stamp. Add the PNG as an image, drag it near the signature line or date field, and resize it to the size of a real stamp, usually 35–45 mm wide on an A4 or Letter page.
4. Check, then download. Zoom to 100% to confirm that names, amounts, and dates are still readable, then download the stamped PDF.

Tips for a clean stamped PDF

• Use a transparent PNG. A JPG brings its white background with it and hides the text underneath; here is how to remove the white box around a digital stamp.
• Let the stamp overlap the signature slightly, the way a wet stamp would, without covering key details. This guide shows how to place a digital stamp without covering PDF content.
• On dark or colored pages, switch the ink to white or a light tone. Read how to make a digital stamp work on dark backgrounds.
• A stamp image is a visual mark, not a certificate-based signature. When a document needs legal e-signing, use a signature service as well and add the stamp for recognition.

Stamping scanned and signed PDFs

Scanned pages are images, so the stamp simply sits on top of them. Match the stamp size to the scan: if the page was scanned at a reduced size, shrink the stamp by the same amount so it does not look oversized. When a PDF already carries a certificate-based digital signature, add the stamp before signing; changing the file afterwards can invalidate the signature.

Which stamp suits which PDF?

Invoices and receipts usually carry a received stamp or a paid mark. Contracts and certificates often use a round corporate seal, delivery notes a date stamp, and outgoing letters an address stamp. Start from the matching template, replace the wording, and export the PNG you will place here.