Is it safe to sign a PDF with this tool?

Yes. Everything — PDF rendering, signature background removal and export — runs locally in your browser. Your documents and signature are never uploaded to any server.

How do I turn a photo of my signature into a digital signature?

Sign on plain paper, photograph it with your phone, and upload the photo. The paper background is stripped automatically using adaptive thresholding, leaving only your ink strokes on a transparent background.

Does the exported PDF have a watermark?

No. The exported file is a standard, flattened PDF with no watermarks and no external dependencies, and it opens in Acrobat, Preview and all browsers.

PDF Signer — Sign PDFs Online Free, Private & In Your Browser

PDF Signer — sign PDF documents online, free and private PDF Signer lets you sign any PDF with your real handwritten signature. Upload a PDF and a photo of your signature, the paper background is removed automatically, and you download a flattened signed PDF. Everything runs locally in your browser — enable JavaScript to use the app.