Assinar PDF
Adicione sua assinatura manuscrita ou em imagem aos seus documentos com privacidade.
Click to select or drop a PDF here
Processed entirely in your browser — never uploaded
Worth thinking about where the signed PDF goes after you sign it. When you send the lease back to your landlord, or the offer letter back to HR, what they receive is a visual signature: your handwriting drawn onto the page, the same class of thing as a scanned wet-ink signature. No CA certificate is embedded, so no reader will tell anyone your identity was verified, or whether the file changed after you signed. And anyone with a PDF editor can erase that signature, or lift it onto a different document. That isn't a MoGuan shortcoming — it's the shared limit of every image-based signature, print-sign-scan included. Decide whether that boundary works for you, then sign: it all happens in your browser, and neither the PDF nor the signature image is uploaded.
FAQ
Is a PDF signed with a drawn signature legally binding?
It depends on what the other party requires and on your jurisdiction, and nothing here is legal advice. Some processes move along fine with a visible signature image; others insist on an identity-verified e-signature service, or a paper original. Ask before you sign rather than after it bounces back. If the other side specifically wants a verifiable certificate-based signature, this tool can't produce one — it draws what a signature looks like, not proof of who signed.
How do I add a handwritten signature to a PDF — draw it or upload an image?
Either. There are two tabs. Draw lets you sign with a mouse or a touchscreen; a finger or stylus on a touchscreen usually looks far more natural than a mouse. Upload image is for a signature you already scanned or photographed — the UI says a transparent-background PNG works best, and it's right: a white-background JPG drops an opaque white rectangle over whatever text sits underneath it. Position it, resize it, then export a new PDF.
Does signing a PDF here upload my file or my signature image?
No. "Upload image" is an awkward phrase on a page that keeps insisting nothing is uploaded — it means picking a file off your own disk and handing it to the browser. That image is handled in browser memory exactly like the PDF: it never leaves your device, and there is no server storing signatures. You can check this the same way as the other classic tools on the site, and signing still works with your Wi-Fi switched off.
Can someone remove my signature from the signed PDF?
Yes. The signature is an image drawn onto the page, so any PDF editor can erase it, or crop it out and paste it onto another document. That is the shared limitation of every image-based signature — printing a page, signing it with a pen and scanning it back has the same weakness, since ink in a scan can be edited out too. Real tamper-evidence needs a certificate-based digital signature, where the reader warns you if the file changed after signing. This tool doesn't do that, and I won't pretend otherwise.
What's the maximum PDF file size I can sign?
50MB free, 100MB on Pro. The gap is a memory constraint: signing reads the whole PDF into browser memory to rewrite it, and pdf-lib's peak usage runs roughly 3–5× the file size, so 100MB is the highest ceiling I'll stand behind and 50MB is a more conservative one. Not every tool on the site raises its limit for Pro — some sit at a hard engine cap that paying can't move. Signing is one that does go up. For anything larger, split the pages first, then sign.