Sign and fill in a PDF

How to add a signature to a PDF

1. 1Open your PDFLoad the document from your device. It stays in the browser throughout.
2. 2Draw or upload your signatureSign directly on the pad with a mouse, trackpad or touchscreen, or bring in an existing image of your signature.
3. 3Place and resize itDrag the signature to the right spot on the page and scale it to match the signature line.
4. 4DownloadExport draws the signature into the page and writes a new file.

A drawn signature is not a digital signature

This tool produces a picture of a signature placed on a page. That is not the same thing as a digital signature, and the difference matters. A digital signature uses a certificate and a private key to cryptographically bind a specific signer to a specific version of the document.

A cryptographic signature proves two things an image cannot: that the named person actually signed, and that nobody has altered a byte of the document since. An image of a signature proves neither — it can be copied off one PDF and dropped onto another in seconds.

For routine paperwork where both sides simply want a visible mark in the right place, this is fine and it is what most people mean by "sign a PDF". For contracts, filings, or anything where the signature may be challenged, use a certificate-based service instead.

Drawing versus uploading

Drawing works best on a touchscreen, where you can sign with a finger or stylus at something close to natural size. With a mouse, sign larger than feels right and scale it down afterwards — the strokes smooth out considerably.

Uploading suits people who already have a scanned signature. Photograph or scan it against plain white paper, crop close, and the result will sit on the page far more cleanly than a snapshot taken at an angle.

Filling in form fields

Many PDFs that look like forms have no interactive fields at all — the boxes are printed lines, not inputs. Text boxes solve this: place one wherever an answer belongs and type into it.

This works the same way on a form that does have real fields; you are drawing on top rather than filling them in. If a document has proper interactive fields and you need them preserved as fields, this is not the right tool.

Flattening

On export, the signature is drawn into the page's own content. It becomes part of the page rather than a separate object floating above it.

That means whoever opens the file cannot simply select the signature and drag it away — but it is not tamper-proof either. Anyone with an editor can cover it, and nothing in the file proves it has not been altered. If that guarantee matters, you need a certificate-based signature.

FAQ

Is this a legally binding electronic signature?

It produces a visual signature, not a certificate-based digital signature, so it cannot prove who signed or that the document is unchanged since. Whether that is sufficient depends on your jurisdiction and the other party. For anything that might be disputed, use a certificate-based service.

Is my signature uploaded to a server?

No. The signature is drawn on a canvas in your browser and written into the PDF locally. It is never transmitted.

Can I reuse the same signature next time?

Not yet — signatures are not stored between sessions, so you draw or upload again each time. Nothing is kept once you close the tab.

How do I remove the white background?

Scan or photograph your signature on plain white paper and crop closely. Backgrounds that are genuinely white blend into a white page; a grey or shadowed photo will show a visible box.

Can someone edit the signature after download?

The signature is flattened into the page, so it is not a draggable object. But it can still be covered or removed with a PDF editor, and nothing in the file detects tampering.