How to sign a PDF
- Open the PDF. Drop it onto the box or tap to pick it. The first page appears on the right (below, on a phone).
- Make your signature. Draw it with a finger, pen or mouse; type your name and pick a handwriting style; or upload a photo of your signature on white paper, and the paper is made transparent.
- Place it. Tap the page where the signature should go, or press Add signature. Drag it into place and pull the round handle to resize it. Use Add date and Add text for the date, your printed name or initials.
- Save. Press Sign and download. The signed PDF downloads to your device.
Use the page arrows to sign more than one page; each page keeps what you placed on it. A selected item can also be moved with the arrow keys (hold Shift for bigger steps), resized with + and −, and removed with Delete.
What the signature looks like in the PDF
Your signature, the date and your text are drawn into the page itself, as sharp transparent images: the signature at three times the resolution of the pad, text at four times its printed size. Because they become part of the page, they look the same in every PDF viewer, in print and in email previews, and the rest of the document is copied as it is, with its text still selectable.
This is a visible electronic signature, the same thing you get by signing a printout and scanning it. Whether that is enough is up to whoever asked you to sign, so check with them if you're unsure. It is not a certificate-based digital signature, the kind that shows a signature panel in Adobe Acrobat and proves the file hasn't changed since. If the sender asks for one of those, or for a qualified signature, use the signing service they name.
Fillable forms
If the PDF has fillable fields, a Lock the form's filled-in fields option appears. Locking (often called flattening) turns what is typed in the fields into part of the page, so the next person can't change it and every app shows it the same way. It starts switched on when every field is already filled in, and off while any field is empty, because that form probably still has to go to someone who fills in the rest. Fill the fields in your usual PDF app first, then sign here.
Your document and signature stay private
The PDF is shown with pdf.js and signed with pdf-lib, both running in your browser from this site. Your signature is never uploaded or saved: close the tab and it is gone, so nobody can reuse it from here. That makes this safe for leases, contracts, consent forms and anything with personal details.
Tips and troubleshooting
- The drawn signature looks shaky: sign more slowly and larger, filling the pad; it is scaled down when placed. On a computer, a trackpad works better with one finger held down than tapping.
- An uploaded signature has a grey box: take the photo in good light on plain white paper, or untick "Remove the paper background" if your image is already transparent.
- "This PDF is encrypted": tap Make an unlocked copy to sign. The signed file then has no password or editing restrictions; add them back in a PDF app if you need them.
- Several documents to sign and send together: sign each, then combine them with Merge PDF. If the result is too big to email, shrink it with the PDF compressor.
- The form wants an image of the signed page: convert it with PDF to JPG.