Sign routine forms
Place a saved signature image on approvals, acknowledgements, internal forms, or other documents where the recipient accepts this signing method.
Stamp a PDF online free
Add a stamp to a PDF — PAID, APPROVED, a company seal, or your signature. Place it on any page, size it, then download a new file. No signup.
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Upload a PDF on the left to get started
Practical guide
How to stamp a PDF with a signature, seal, or logo
Stamping is a visual way to approve, acknowledge, label, or sign a document. The editor renders every page of your file, then drops a saved image wherever you click, centered on that point at a quarter of the page width. You can drag it, resize it from its corner, and export a new copy. Your browser does the PDF work. The only thing stored on our side is an image you choose to add to the stamp library.
- 25%
- Width of a newly placed stamp as a share of the page width, before you resize it. The image keeps its own proportions.Measured in the StampAPDF editor source
- 1,200 px
- Longest edge an image may keep when you add it to the library. Anything larger is scaled down, and every image is stored as a PNG.Measured in the StampAPDF editor source
- 595 x 842 pt
- An A4 page in PDF points, at 72 points to the inch. A default 25% stamp on A4 is about 149 pt, or 52 mm, wide.ISO 32000-1 user space unit; A4 from ISO 216
How to stamp a PDF in 3 steps
- 1
Open the PDF
Choose the document from your device with the file picker on the left. The editor renders each page in the workspace without uploading the PDF to StampAPDF.
- 2
Add and place an image
Use + Add to put a signature, stamp, initials, or seal in the library. A PNG, JPG, or WebP file works, and every image is saved as a PNG. Click the thumbnail, then click the page where the mark belongs.
- 3
Adjust and download
Drag the mark into position, resize it with the small square at its bottom right, check every stamped page, then choose Download stamped PDF.
Worked examples
| If you need to | Do this | You get |
|---|---|---|
| Sign one line on a contract | Click your signature in the library, then click the signature line | The image lands centered on the point you clicked, a quarter of the page wide |
| Stamp PAID on a three-page invoice | Click the stamp and click page 1, then click the stamp again for each further page | Three independent copies you can move and size one at a time |
| Fit a seal inside a small box on a form | Click the mark, then drag the square handle at its bottom right | Width and height shrink together, down to 3% of the page width, with proportions locked |
| Undo a mark you put in the wrong place | Click it and press Delete, or use the round × on its corner | The mark goes, and the page underneath is unchanged |
| Keep the file you started from | Stamp invoice.pdf and choose Download stamped PDF | A separate file called invoice-stamped.pdf; the original is never rewritten |
When to stamp a PDF
Mark invoices and receipts
Reuse a PAID, RECEIVED, or APPROVED stamp while keeping the amount, reference number, and existing text visible.
Add company marks
Place a business stamp, department seal, or authorized mark in a designated box without printing and scanning the document again.
Initial specific pages
Use a compact initials image beside clauses or at the foot of selected pages when a workflow asks for page-by-page acknowledgement.
Tips to stamp a PDF well
- Crop a transparent PNG to the ink so the stamp does not cover nearby text with a white rectangle.
- Match the on-page size to a real signature or rubber stamp. The default width is a quarter of the page, which is wider than most signature lines need, so resize before you download.
- Check every stamped page before downloading so the mark does not hide dates, amounts, names, form fields, or signature instructions. The editor has no zoom control, so use your browser's zoom for a closer look.
- The download is named after your file with -stamped added, so contract.pdf arrives as contract-stamped.pdf. Rename it afterwards if you want a date or a version in the filename.
- With a mark selected, Delete or Backspace removes it, which is quicker than aiming for the small × when you are working through several pages.
Good to know
- A signature image lacks the identity verification and tamper evidence of a certificate-based digital signature. Laws and recipient requirements vary, so confirm the accepted method for important legal, financial, or government documents.
- The stamp library is not tied to an account or to your device. An image you add is stored in StampAPDF's database and is listed for anyone else using the tool, so treat it as shared rather than private and do not save a personal signature you would not want a stranger to see. The × on a thumbnail deletes it from the database.
- The editor places images only. There is no text box, date field, or rotation control, so put any wording, name, or date into the image before you add it to the library.
- A password-protected PDF cannot be opened here. Remove the password in the application that produced the file, then stamp the unprotected copy.
- Stamping a PDF can invalidate an existing certificate signature. Add visual marks before the certificate signing step when your workflow requires both.
Questions about how to stamp a PDF
▸How do I stamp a PDF online?
Open the PDF in the editor, add a signature or stamp image to the library with + Add, click the thumbnail, then click the spot on the page where the mark belongs. Drag it to fine-tune the position, resize it from the square handle at its bottom right, and choose Download stamped PDF. There is nothing to install and no account to create.
▸Can a pasted signature image create a binding signature?
A recipient may accept it in many everyday electronic-signature workflows, but legal effect depends on the document, jurisdiction, evidence of intent, and the recipient's rules. A signature image does not provide the identity verification or tamper evidence of a certificate-based digital signature.
▸What image format works best for a signature?
Use a transparent PNG so the ink appears without a background. Crop empty margins first so placement and resizing match the intended mark. A JPG or WebP file works too and is converted to PNG on the way in, though a JPG cannot carry transparency. An image longer than 1,200 pixels on its longest edge is scaled down before it is saved.
▸Is my PDF uploaded or stored?
No. Your browser opens, edits, and exports the PDF on your device. Reusable signature and stamp images are the exception: an image added to the library is stored in StampAPDF's database, and that library is shared by everyone using the tool rather than kept private to you.
▸Can I stamp more than one page?
Yes. Each click places one mark, and the selection clears afterwards, so click the library thumbnail again before placing the next copy. Every copy can then be moved, resized, or removed on its own before you download.
▸Where does the stamped PDF get saved?
It goes to whatever folder your browser uses for downloads, under the original name with -stamped added, so invoice.pdf becomes invoice-stamped.pdf. The file you opened is not modified, so the untouched original stays where it was.
▸Can I use the same stamp on other PDFs?
Yes. An image stays in the library after you place it, and it is still there on a later visit, so you can open a different document and reuse the same mark without adding the image again. Delete it with the × on its thumbnail when you no longer need it.
Learn more
How to sign a PDF without printing
Prepare a clean signature image, place it in the right spot, and learn when you need a stronger signing method.
How to stamp PAID on an invoice
Build a reusable invoice stamp and position it without covering amounts, dates, or reference numbers.
Are online PDF tools safe?
Learn how to distinguish file uploads from local browser processing before working with sensitive documents.