How to sign a PDF in your browser — and what an electronic signature is and is not
Most documents that need a signature are ordinary: a lease, an offer letter, a consent form, a supplier's terms, the school trip permission slip. Printing, signing, scanning and emailing them back is the workflow everyone knows and nobody enjoys, and the online alternatives ask you to upload the very document you were careful about. Sign PDF does the whole thing on your device: the file is rendered in your browser, your signature is drawn, typed or photographed there, and the signed PDF is written there. This guide walks through the three ways to make a signature, how to place it well, and — because it matters — what kind of signature you end up with.
Electronic or digital: which one this makes
Two words get used interchangeably and mean different things. An electronic signature is a mark on the page: your handwritten signature drawn with a finger, your name in a script font, a photo of the signature you put on paper. It shows intent the way ink does. A digital signature is cryptographic: a certificate issued to you signs the file, and a reader can verify who signed it and that not a byte changed since. Sign PDF makes the first kind. It cannot make the second, because that needs a certificate and a private key that identify you, and no free web page should pretend otherwise.
Is the first kind enough? Usually, for everyday agreements between people who know each other: many jurisdictions accept an electronic signature as long as both sides intended to sign. Some documents — certain official filings, financial instruments, cross-border contracts, anything a notary would normally witness — require a certified digital signature or a particular signing service. The tool cannot know which document you hold, so the honest rule is: if the sender specified how to sign, follow that; if not, an electronic signature is what they are expecting.
Three ways to make the signature
Draw. The pad records your strokes at your screen's resolution, so a signature drawn with a finger on a phone or a pen on a tablet comes out smooth. A mouse is workable — sign slowly and larger than you would on paper. The empty space around the strokes is trimmed away, so what you place is only the ink, and you can pick black or blue.
Type. Type your name and pick one of three handwriting styles — a casual one, a flowing one and a formal one. The fonts are bundled with the site under an open licence and cover accented and extended Latin letters, so Ayşe, Søren and Zoë render as typed. The result is a picture in the style you chose, which means the PDF needs no font installed anywhere.
Upload. If you already have your signature on paper, photograph it or scan it and upload the picture. With Remove white background on (the default), paper and light backgrounds become transparent and only the darker ink is kept, so the signature sits on the page instead of arriving inside a white rectangle. Turn it off for a company stamp or logo that should keep its background. The picture is opened on your device like every other image on the site.
Signatures live in the tab's memory for the session: create up to five, place them as often as you like, and they are gone when you reload. Nothing is written to storage, because a signature is the last thing that should linger on a shared computer.
Placing the signature, the date and initials
- Add the PDF. The first page appears; use Previous, Next or the page number to reach the signature line.
- Click Place beside a signature. It lands in the middle of the page; drag it onto the line and pull the corner to size it. Arrow keys nudge it by 1 % (Shift for 5 %), plus and minus resize it, Delete removes it.
- Add a Date — today's date in your device's format, editable — and any Text the form asks for: a name in print, a place, a title. Latin text is written as real text in Helvetica; other scripts are drawn as a sharp picture.
- For a contract that wants initials on every page, click Initials (a small copy of the signature) and switch on Every page; it repeats at the same spot on all pages.
- Click Sign PDF, check the preview, download, and page through the file before sending it.
Everything is positioned relative to the page as you see it, so the result matches the screen at any zoom, and a scanned page stored sideways still gets the signature where you put it. Pictures keep their proportions; a date or text scales its letters with its width.
Forms, existing signature fields and what changes in the file
Many contracts arrive with empty signature fields drawn by the sender's software. Those are fine: Sign PDF leaves the field in place and you put your signature over it. What it refuses is a document that already carries a digital signature or a certification, because saving a new copy would invalidate that signature — if a counterparty has digitally signed first, they have chosen a certificate-based workflow and you will need the same kind of tool. It also refuses encrypted PDFs (remove the password with Unlock PDF first) and XFA forms.
Items are drawn into the pages in place, not copied into a new document, so the file's text, pictures, links, bookmarks, annotations, editable form fields and metadata stay as they are. The signed file is a new file named after the original with -signed added; your original is untouched. Because the signature becomes page content, it can be removed by anyone with a PDF editor — the same is true of every free web signer. If the signed file should not be edited, send it to Protect PDF and block editing or add a password; if it is a scanned contract that grew large, send it to Compress PDF first.
Several signers
Sign your copy and pass the file on. The next person opens the signed PDF here, adds their own signature and sends it back; each signing produces a new file, so keep the version you sent. This is how paper works too, and for most agreements it is enough. If you need a record of who signed when, with reminders and a verifiable audit trail, that is what a signing service sells — and what uploading your document to it buys you.