deskutil

Converter tool

Sign PDF

Stamp a drawn or uploaded signature image onto one PDF page in your browser, then download signed.pdf. This is not a legally binding digital or certificate signature. Password-protected PDFs fail with a clear error. Nothing is uploaded.

This stamps a PNG or JPG image onto a page with pdf-lib. It is not a certificate-based digital signature. Work stays in the browser. Large files may be slow.

Choose one PDF or drop it here. Nothing is uploaded.

Draw a signature

Draw with mouse or touch. Or upload a PNG or JPG of a signature instead.

No image uploaded. The canvas drawing will be used if you sign without a file.

File—
Pages—
Size—

Choose one PDF, draw or upload a signature, pick a page, then sign. Files around 40 MB or many pages may be slow.

How to use Sign PDF

Choose or drop one PDF. Draw a signature on the canvas with mouse or touch, or upload a PNG or JPG. Enter the page number. Optional X and bottom offsets move the stamp from the default near-bottom position. Then Sign PDF to download signed.pdf. This only stamps an image. It is not a legally binding digital or certificate signature. Password-protected files fail with an error. Nothing is sent to a server.

Frequently asked questions

Is this a legally binding digital signature?

No. This stamps a drawn or uploaded image onto a PDF page. It is not a legally binding digital or certificate signature, and it does not use PKI, certificates, or cryptographic signing.

How does Sign PDF stamp a signature?

You draw on a canvas or upload a PNG or JPG. pdf-lib embeds that image with embedPng or embedJpg and draws it near the bottom of the page you choose. Optional offsets move it from that default corner.

What happens with a password-protected PDF?

Signing stops with a clear error. Remove the password in another app, then try again. The file is never uploaded.

Is my PDF uploaded to a server?

No. pdf-lib runs in your browser, signed.pdf is built locally, and Deskutil never receives the file or the signature image.

What file do I download?

A single PDF named signed.pdf. The chosen page has the image stamped near the bottom. Other pages are unchanged. This is still just an image stamp, not a certificate signature.