Signing a PDF is one of the most common document tasks. Contracts, leases, permission forms, tax documents, and employment agreements all need signatures. Our tool lets you create a signature — by drawing, typing, or uploading an image — and place it directly onto any page of a PDF. The entire process runs in your browser. No account, no upload, no server.

Three ways to create your signature

Draw. Use your mouse, trackpad, or stylus to draw your signature freehand on a canvas. This produces the most natural-looking result and is the closest to signing with a pen.

Type. Enter your name and the tool renders it in a script-style font. This is the fastest option and produces a clean, consistent signature every time.

Upload. If you already have a signature image (from a scan, a tablet app, or a previous signing), upload the PNG or JPG file directly. The tool will embed it as-is.

All three methods produce a PNG image that is embedded into the PDF page at the coordinates you choose. The background is transparent, so the signature blends naturally with the page content.

How it works

After creating your signature, you upload a PDF. The tool renders each page as a preview thumbnail. Click anywhere on a page to place your signature at that location. You can place multiple signatures — for example, initials on every page and a full signature on the last page.

When you are satisfied with the placements, click to sign and download. The tool uses pdf-lib to embed each signature image directly into the PDF page content stream. The result is a standard PDF that can be opened in any PDF viewer and will display the signature exactly where you placed it.

The key technical details:

1. Your signature is converted to PNG. Whether drawn, typed, or uploaded, the signature is represented as a PNG image with a transparent background.
2. The PDF is loaded with pdf-lib. The library parses the document structure in your browser's memory.
3. Each signature image is embedded. For each placement, the PNG is embedded into the destination page using embedPng() and drawImage() at the specified coordinates.
4. A new PDF is saved. The modified document is serialized to bytes and downloaded.

No page content is modified except for the addition of the signature images. Text remains searchable, links remain clickable, and form fields remain interactive.

Visual vs. digital signatures

There is an important distinction between what this tool does and what cryptographic digital signing tools do:

Visual signature (what this tool provides): An image of your signature placed on the page. It proves intent to sign in the same way a pen-on-paper signature does. Accepted for most everyday documents.

Cryptographic digital signature (not what this tool provides): A certificate-based signature that mathematically proves the signer's identity and detects any subsequent modifications to the document. Required for certain legal, financial, and government contexts.

For most personal and business use cases — signing a lease, a permission slip, an NDA, an internal form — a visual signature is sufficient. If your use case requires a certificate-based digital signature, you will need a specialized tool or a signing service that issues certificates.

Privacy

Your signature is sensitive personal data. On most signing platforms, your signature is uploaded to their servers, stored in their database, and associated with your account. With PDF Cloak, your signature never leaves your browser. It exists only in your tab's memory for the duration of the session. When you close the tab, it is gone. We have no account system, no database, and no server-side processing. Your signature touches one machine: yours.