Sign PDF (draw or image)
Stamp a typed or image signature onto a page. Not a certificate/PKI signature.
Runs on your device. The file is never uploaded.
Sign PDF stamps a signature onto the last page of your document, or onto a page you name. Typed text comes out in Helvetica Oblique at 22 points with a rule under it. A PNG or JPG dropped alongside wins over the text, placed 160 points wide by default. Only the first PDF you drop is signed.
Questions
Is this a legally binding digital signature?
No, and the tool is explicit about it. This stamps a picture of a signature onto a page, exactly the way the watermark tool stamps text. A certificate-based signature is a different thing: a detached CMS signature over the document byte range, with a trust chain and a signature form field. None of that is built here.
How do I supply the signature?
Two ways. Type it into the text field and it is drawn in Helvetica Oblique at size 22 in dark blue, with a ruled line underneath. Or drop a PNG or JPG alongside the PDF and that image is stamped instead. If both are given the image wins and the text is ignored.
Which page gets signed?
The last page by default. Type a page number to choose another one; it must be between 1 and the document's page count, and you get "page must be between 1 and N" if it is not. Only one page is signed per run, placed 36 points in from the left and bottom edges.
Why does it say "drop the PDF to sign"?
Because no file ending in .pdf was among the ones you dropped. This tool takes several files at once so it can pair a PDF with a signature image, and it picks the PDF by extension. If you gave a PDF but neither text nor an image, you get a different message asking for signature text or a PNG or JPG.
How big will the signature be?
The width setting decides, in points, defaulting to 160. An image keeps its aspect ratio: the height is worked out from the width you asked for and the image's own proportions. Typed text ignores the width and is drawn at a fixed size of 22 points, so the width setting only applies to images.
Does my signature image get uploaded?
No. Both the PDF and the image are read into a Web Worker in this tab, combined by pdf-lib, and handed back as a file with a -signed suffix. A scanned signature is about as sensitive as a file gets, and this one never goes anywhere near a network.