Add visible marks to PDFs
right in your browser.

Many online document tools ask you to upload your file before you can add a visible signature or other mark. For contracts, offer letters, tax forms, and other sensitive paperwork, that means trusting a third party with confidential information. This editor instead opens, renders, and marks your PDF inside the browser tab. The document is not sent to a processing server.

Common use cases

• Contracts and agreements — Add a visible signature mark to a review copy before returning it.
• Offer letters and HR forms — Add requested visible marks while keeping document processing local.
• Government and tax forms — Add a visible mark where requested, then confirm the recipient accepts that format.
• Permission and consent forms — Mark a local copy on a phone or laptop and confirm the receiving workflow's requirements.

Three ways to create a signature

Draw lets you sign with a mouse, trackpad, or touchscreen — closest to a handwritten signature. Type renders your name in a script or print style, ideal when you just need a clear mark. Upload lets you reuse a photo or scan of your real signature; a transparent PNG blends most naturally onto the page.

How browser-based PDF marking works

The editor renders each PDF page with pdf.js so you can position marks. On export, pdf-lib writes those visible images into a new PDF copy at the selected positions and sizes. Export and download are separate: the result stays available until you explicitly save it or make another edit. Editing a PDF that contains prior digital signatures may invalidate them.

This creates visible electronic marks only. It does not create, validate, or preserve a certificate-backed digital signature, and it does not determine whether a recipient will accept the marked copy.