How to Sign a PDF on Windows

Using Microsoft Edge instead

Edge opens PDFs by default on many Windows PCs. Its built-in PDF viewer has annotation tools in the toolbar, including a drawing tool you can use to write your signature with a mouse, pen or touchscreen, and a text tool for the date. Save the file when you are done.

Drawing with a mouse can look rough. A saved, reusable signature in Acrobat Reader or a typed signature often looks cleaner.

A browser-based option

If you would rather not install anything, eSignSimple's free Sign PDF tool is included with a free account (sign up with Google) and runs in your browser. You upload the PDF (it is encrypted at rest), draw or type a signature, add the date, and download the signed copy with an audit trail; it counts as one of your monthly documents.

It works in Edge, Chrome or Firefox on Windows.

Why does my PDF open in the wrong app?

Windows often sets Microsoft Edge as the default PDF viewer. To use Acrobat Reader instead, right-click the file, choose Open with, pick Adobe Acrobat and tick the option to always use it, or change the default under Settings > Apps > Default apps. If you cannot type or sign in Acrobat, the document may be protected; the file's security properties will say so.

If you are signing on a laptop with a touchscreen, use a finger or pen in Edge's draw tool for a more natural signature than a mouse can produce.

Common mistakes when signing PDFs on Windows

Saving the signed file into a temporary folder and then attaching the unsigned original to your reply is surprisingly common; attach from the folder where you saved it and open it once to check. Another is signing a document that still needs details filled in: complete the fields first, as covered in how to fill out a PDF. And if the other party asks for your signature in a Word file rather than a PDF, see how to electronically sign a Word document.

For a quick legal sanity check, are electronic signatures legally binding explains when a simple signature is enough and when it is not.

Edge, Acrobat Reader or a browser tool: which works best on Windows?

Edge is already there and opens PDFs by default on most Windows PCs, which makes it the quickest option for a one-off signature. Its weakness is that it has no saved signature, so you draw or type it every time, and a mouse-drawn signature looks rough. Acrobat Reader takes a few minutes to install but saves your signature and initials for reuse, which matters if you sign more than a couple of documents a month.

A browser tool is the middle ground for shared or locked-down PCs where you cannot install software. On a work laptop managed by your IT team, check your company's rules first: some organisations block PDF editing apps or route files through approved tools only, and a browser tool may be the only route that does not need an admin password.

How do I make a mouse signature look less messy?

A signature drawn with a mouse has two problems: the strokes are jerky and the proportions are off. Draw large and slowly, then shrink it on the page; scaling down hides most of the wobble. Use a single continuous movement where you can, since stop-start strokes look worse. Many people find a trackpad with a finger smoother than a mouse.

The better answer is to avoid the mouse altogether. Type your signature in a script font, which is just as valid in most places and always legible. Or draw it once on your phone, save it as an image with our signature generator, and insert that image in Acrobat Reader. A touchscreen laptop or a pen tablet gives the most natural result if you have one.

Signing a PDF on a shared or public computer

Libraries, hotel business centres and office hot desks are common places to sign something in a hurry. The risk is what you leave behind: a copy of the signed PDF in Downloads, your saved signature inside Acrobat, or your email still logged in. Before you leave, delete the downloaded and signed files, empty the recycle bin if the computer allows it, remove any saved signature from the app, and sign out of your mail.

A safer pattern on a shared PC is to open the document in a private browser window, sign it with an in-browser tool, and download or email the result directly. When the window closes, the browser discards its session data. And if the sender offers a signing link, use it: you sign in the browser, nothing is saved to the computer, and the completed copy arrives in your own inbox.

Microsoft Print to PDF: a simple way to lock your signature in

Windows includes a virtual printer called Microsoft Print to PDF. After signing in Edge or Acrobat, open the print dialog, pick Microsoft Print to PDF as the printer, and save the new file. The output is a flattened PDF in which the signature is part of the page and cannot be selected or dragged in another viewer.

Two caveats. Printing to PDF removes interactive form fields, so do it only once everything is filled. And it creates a new file rather than replacing the old one, so name it clearly. If the recipient later needs to prove the document has not been changed, a flattened copy helps, but a signing service with a certificate and fingerprint does a far better job; see how to verify an electronic signature.

Our take

Sources and further reading

• Sign PDFs in Adobe Acrobat Reader – Adobe Help
• ESIGN Act, 15 U.S.C. § 7001 – general rule of validity (Cornell LII)