Sign a PDF

How it works

Upload a PDF, then draw your signature in the white box using your mouse, trackpad, or finger. The blank space around your ink is trimmed automatically, so the signature you place is exactly what you drew. Your signature then appears as a movable box on the page preview — drag it onto the signature line, use the size slider to match the space, and flip to another page if you need to sign there instead. When you download, the signature is written into the page itself using pdf-lib, entirely in your browser. Your document never touches a server.

When to use this

• Returning a signed contract, lease, or offer letter without printing and scanning
• Signing a permission slip, waiver, or intake form that arrived as an attachment
• Approving an invoice or purchase order that needs a real signature, not a typed name
• Signing on a phone or tablet, where a finger gives a more natural signature than a mouse
• Handling a document you'd rather not upload to a service that keeps a copy

Common mistakes

• Signing the wrong page — the signature lands on the page shown in the preview, so check the page number before downloading
• Making the signature too large — start around a quarter of the page width and size down from there
• Expecting a certificate-based digital signature — this places a visible signature image, which is what most everyday forms need, but it carries no cryptographic audit trail
• Trying to sign a password-protected PDF — remove the password in your PDF reader first
• Drawing too small on the pad — use most of the box, since the ink gets scaled to fit wherever you place it