How to Add a Signature to a PDF for Free

You can sign a PDF for free two ways without installing anything extra: draw your signature right in Microsoft Edge’s built-in PDF reader, or use Adobe Acrobat’s free online Fill & Sign tool to type, draw, or upload a signature image. Neither creates a legally certified digital signature — for that you need a certificate-based Digital ID, which is a separate, stronger tool covered below.

Sign a PDF in Microsoft Edge with the Draw tool#

Edge’s PDF viewer has had a built-in inking feature for years, and it works for quick signatures on forms, acknowledgments, and approvals.

1. Right-click the PDF and choose Open with > Microsoft Edge, or drag the file into an Edge window.
2. In the PDF toolbar at the top, click Draw.
3. Pick a pen color and stroke thickness from the options next to the Draw button.
4. Use a mouse, touchscreen, or stylus to write your signature directly on the page.
5. Use Erase to remove a stroke if it comes out wrong, then redraw it.
6. Click Save to overwrite the file, or Save as to keep the original and create a signed copy.

This is genuinely fast, but it has real limits. You can’t save a signature to reuse later, so you’re redrawing it with a mouse every time unless you have a touchscreen or pen. It’s also not a verifiable digital signature — Edge can view and check certificate-based signatures in a PDF, but the Draw tool itself just adds ink strokes, not cryptographic proof of who signed or whether the file changed afterward.

Sign a PDF with Adobe Acrobat’s free online Fill & Sign tool#

Adobe’s Acrobat online tools let you fill and sign a PDF in any browser with a free Adobe account — no paid subscription needed for basic signing.

1. Go to Adobe’s Fill & Sign page and upload your PDF (drag and drop or Select a file).
2. Sign in with a free Adobe account when prompted; this is required to save or download the finished file.
3. Open the Sign panel and choose to add your signature.
4. Create your signature using one of three tabs: Type (pick a script-style font), Draw (sketch it with your mouse or touchscreen), or Image (upload a photo or scan of your handwritten signature, ideally on a plain white background).
5. Click on the page where the signature should sit, then resize or reposition it as needed.
6. Repeat for any date or initial fields, then click Next to finish and download the signed PDF.

Because your signature is saved to your Adobe account, this method is faster than Edge if you sign documents regularly — you reuse the same signature without redrawing it. The desktop version of Adobe Acrobat Reader has the same Fill & Sign panel (Tools > Fill & Sign) if you’d rather work offline once the file is downloaded.

Drawn signature vs. a secure digital (certificate) signature#

These two things get lumped together as “signing a PDF,” but they solve different problems. A typed, drawn, or uploaded image signature is a visual mark — it shows intent to sign but doesn’t prove identity or detect tampering. A certificate-based digital signature uses a Digital ID (a cryptographic key pair) to sign the file’s contents; if so much as a character changes afterward, the signature shows as invalid when the document is reopened.

Signature type	How it’s made	Proves identity?	Detects tampering?	Best for
Drawn/typed/image signature	Edge Draw tool, Acrobat Fill & Sign	No	No	Internal forms, quick approvals, low-stakes acknowledgments
Self-signed Digital ID	Free Adobe Acrobat Reader: Tools > Certificates > Digitally Sign, then create a new Digital ID	Only to the extent you trust the signer’s own claim	Yes	Documents you control that need tamper-evidence but not third-party verification
CA-issued digital certificate	Purchased from a certificate authority, used the same way in Acrobat’s Certificates tool	Yes, verified by a third party	Yes	Contracts, legal filings, anything needing court-grade proof of signer identity

If you only need to acknowledge a form or approve something informally, the drawn signature from Edge or Acrobat’s Fill & Sign is enough and it’s free. If the document needs to prove who signed it and that it wasn’t altered afterward, use Acrobat Reader’s Certificates tool to create a Digital ID — a self-signed one is still free, though it only proves as much as people are willing to trust your own claim of identity. For anything with real legal weight, a CA-issued certificate is the only option that a court or counterparty will treat as verified.

Which method to use#

If you need to…	Use
Sign one form quickly on a Windows PC	Edge’s Draw tool
Reuse the same signature across many documents	Adobe Acrobat online Fill & Sign
Prove the file wasn’t edited after signing	A self-signed Digital ID in Acrobat Reader
Meet a legal or compliance requirement for signer identity	A CA-issued certificate

Before you sign anything sensitive, double-check that you’re on the real Adobe site and not a lookalike; PDF-signing pages are a common target for phishing attempts. If you’re also editing the document’s text or layout before you sign it, see our guide on how to edit a PDF for free; if you just need to shrink the file after signing, our guide on how to compress a PDF file covers that.

For most people, the right call is simple: draw it in Edge or Acrobat for anything routine, and only bother with a Digital ID when someone specifically needs to verify the signature later.