How to Sign a PDF for Free: Add Electronic Signature Without Adobe

Quick summary: To sign a PDF for free on Mac, open it in Preview, click the Markup Toolbar, click the Signature button, and draw or type your signature — then drag it into place on the document. On Windows, open the PDF in Adobe Acrobat Reader (free), go to Fill & Sign, and add a typed or drawn signature. On iPhone, open the PDF in Files, tap the markup pencil, tap the + button, and choose Signature.

Signing a PDF electronically is faster and more practical than printing, signing by hand, and scanning. All methods below produce a legally valid electronic signature under most jurisdictions — the PDF format stores the signature as an embedded image. For documents that require a cryptographic digital signature (contracts, legal filings requiring certified e-signatures), use a dedicated e-signature platform. After signing, you can upload the signed PDF to our free AI PDF reader to extract and review the content.

How to sign a PDF on Mac

Method 1: Preview (built-in, free)

Preview has a full signature tool that captures, stores, and applies your signature:

Create your signature (first time only):

1. Open any PDF in Preview.
2. Click the Markup Toolbar button (pencil icon) or go to View → Show Markup Toolbar.
3. Click the Signature button (looks like a cursive signature).
4. Choose how to create your signature:
   • Trackpad: Click “Trackpad,” click the field, and write your signature with a finger on the trackpad. Press any key when done.
   • Camera: Click “Camera,” sign your name on white paper, and hold it up to the camera. Preview captures the signature outline.
   • iPhone/iPad: Click “iPhone” or “iPad” — the Continuity Camera feature lets you draw your signature on your phone screen.

Apply the signature:

1. After creating, Preview saves it for future use.
2. Open the PDF you want to sign.
3. Click the Signature button in the Markup Toolbar.
4. Select your saved signature — it appears as a draggable element on the page.
5. Drag it to the signature line.
6. Resize by dragging the corner handles.
7. File → Save or File → Export as PDF to save the signed document.

Method 2: Quick Look + Markup

1. Select the PDF in Finder.
2. Press Space to open Quick Look.
3. Click the Markup button (pencil icon in the top right).
4. Use the Signature tool same as Preview.

How to sign a PDF on Windows

Method 1: Adobe Acrobat Reader (free)

Acrobat Reader’s Fill & Sign tool works on any PDF:

1. Open the PDF in Acrobat Reader (free).
2. Go to All Tools → Fill & Sign, or look for the pen icon in the toolbar.
3. Click “Sign yourself” → “Add Signature”.
4. Choose:
   • Type: Type your name — choose a cursive font style.
   • Draw: Draw your signature with the mouse.
   • Image: Upload an image of your handwritten signature.
5. Click Apply.
6. Click where you want to place the signature on the page.
7. File → Save to save the signed PDF.

Method 2: Microsoft Edge

Edge has a basic drawing tool but no dedicated signature feature. For a simple initial or name:

1. Open the PDF in Edge.
2. Click the Draw button in the PDF toolbar (pencil icon).
3. Draw your signature directly on the page.
4. Click the download button to save.

This produces a hand-drawn annotation rather than a formal signature. For a cleaner result, use Acrobat Reader.

How to sign a PDF on iPhone

Method 1: Files app (built-in)

1. Open the PDF in the Files app.
2. Tap the Markup button (pencil icon, top right).
3. Tap the + button (bottom right of the toolbar).
4. Tap “Signature”.
5. Draw your signature with your finger on the screen.
6. Tap Done.
7. Drag the signature to position it on the signature line.
8. Resize by dragging the corners.
9. Tap Done at the top → “Save File” when prompted.

Method 2: Mail app

If the PDF was sent as an email attachment:

1. Open the email in Mail.
2. Tap the PDF attachment.
3. Tap the Markup button (top right).
4. Add your signature using the + → Signature method above.
5. Tap Done → the signed PDF is ready to send or save.

Types of PDF signatures

Type	What it looks like	Legally binding?
Typed signature	Your name in a cursive font	Yes, in most jurisdictions
Drawn signature	Hand-drawn via trackpad/mouse/finger	Yes, in most jurisdictions
Image signature	Photo of handwritten signature	Yes, in most jurisdictions
Digital signature (cryptographic)	Certificate-based, invisible or visible mark	Highest legal standing; requires a signing certificate

For standard business documents, typed or drawn signatures are accepted in the US (ESIGN Act), EU (eIDAS), and most other jurisdictions. Certified digital signatures are required for some legal, government, and financial documents.

How to position and resize a signature

After placing the signature on the page:

• Move: Click and drag the signature element.
• Resize: Drag the corner handle (not the side handles, which may distort the signature).
• Delete and redo: If the placement is wrong, press Delete or Cmd+Z and re-place.

In Preview, the signature is an annotation layer — you can still move it until you flatten the PDF. In Acrobat Reader, signatures placed via Fill & Sign are also movable until you save and close.

How to remove a signature from a PDF

If the signature has not been flattened (saved as part of the page image):

• Preview: Open the PDF → show Markup Toolbar → click the signature annotation → press Delete.
• Acrobat Reader: Right-click the signature → Delete.

If the PDF has been flattened (the signature is baked into the page), you cannot remove it without editing the underlying image.

Frequently Asked Questions (FAQ)

Is signing a PDF electronically legal?

In most countries, yes. Electronic signatures are legally binding under the US ESIGN Act (2000), EU eIDAS Regulation, and similar laws in Australia, Canada, UK, and most other jurisdictions. For government filings, court documents, or contracts requiring a notarized or certified digital signature, check the specific legal requirements — those may require a cryptographic certificate-based signature from a qualified trust service provider.

What is the difference between an electronic signature and a digital signature?

An electronic signature is any mark added electronically to indicate agreement — a typed name, drawn signature, or image. A digital signature is a cryptographic stamp tied to a certificate that verifies the signer’s identity and detects if the document was modified after signing. Digital signatures have higher legal standing and are required for some regulated documents.

How do I add initials to a PDF instead of a full signature?

Use the same method — draw or type your initials instead of your full signature. In Preview, create an “initials” signature variant. In Acrobat Reader, the Fill & Sign tool has a separate “Add Initials” option next to “Add Signature.”

Can I reuse my signature across multiple PDFs?

Yes. Preview stores your signature for reuse — click the Signature button in any PDF and select the saved signature. Acrobat Reader also saves signatures for reuse in the Fill & Sign tool. You do not need to recreate it each time.

How do I sign a password-protected PDF?

Remove the password first — see how to remove a password from a PDF for free — then sign the unlocked PDF.

Does signing a PDF change the original file?

Only if you save (overwrite) the original. Use Save As or Export as PDF to keep the unsigned original and create a new signed copy.

Related guides

• How to add a signature to a PDF for free — alternative methods and image-based signatures
• How to fill out a PDF for free — fill in form fields before signing
• How to flatten a PDF for free — lock the signature into the page after signing
• How to remove a password from a PDF for free — unlock before signing
• How to redact a PDF for free — remove sensitive content before signing and sharing