The days of printing, signing, and scanning a document are over. You can sign a PDF digitally in seconds — for free, without Adobe Acrobat Pro, and without leaving your browser. This guide covers every method for signing PDFs on any device.
Method 1: Free Browser-Based PDF Signer (No Upload, No Account)
PDFWonder's Sign PDF tool adds a typed signature to any PDF page. Choose the page, position, font size, and colour. All processing happens locally in your browser.
- Go to the Sign PDF tool.
- Upload your PDF.
- Type your name or initials in the signature field — a cursive preview appears.
- Select the page number and position (bottom-right is the most common for signatures).
- Click Add Signature & Download.
- The signed PDF downloads to your device.
Method 2: Sign a PDF in Adobe Acrobat Reader (Free App)
Adobe Acrobat Reader (free on Windows, Mac, iOS, Android) has a built-in Fill & Sign feature that supports typed, drawn, and image-based signatures:
- Open the PDF in Adobe Acrobat Reader.
- Click Fill & Sign in the right-hand panel (or Tools menu).
- Click the pen icon to add a signature.
- Choose Type (enter your name), Draw (draw with mouse/finger), or Image (upload a photo of your handwritten signature).
- Click Apply, then click the page where you want to place the signature.
- Resize and position, then save the PDF.
Method 3: Sign a PDF on iPhone (Built-in, Free)
Apple's iOS has built-in PDF signature support:
- Open the PDF in the Files app or in Mail.
- Tap the Markup icon (pen icon at the top).
- Tap the + button in the Markup toolbar.
- Tap Signature.
- Draw your signature with your finger or Apple Pencil.
- Tap Done — then drag the signature to the correct position on the document.
- Tap Done again and save.
iOS saves your signature for future use so you do not need to draw it every time.
Method 4: Sign a PDF on Android (Free)
Android does not have a native PDF signature feature, but several free options work well:
- Adobe Acrobat Reader (free app): Download from Google Play and use the Fill & Sign feature as described above.
- Microsoft Office Lens + Word: Photograph your written signature → use Word to insert it as an image into the PDF.
- PDFWonder in Chrome: Works in mobile Chrome just like on desktop.
Method 5: Sign a PDF on Mac with Preview (Free, Built-in)
- Open the PDF in Preview.
- Click the Markup Toolbar button (pencil icon in toolbar).
- Click the Signature button (looks like a cursive signature).
- Choose Create Signature — use your trackpad, camera (photograph a written signature), or iPhone/iPad.
- Click on the signature to insert it, then drag it to the correct position.
- Save the PDF (File → Save or Cmd+S).
Method 6: Sign a PDF in Microsoft Word
If you receive a PDF and can convert it to Word first:
- Open Word → File → Open → select the PDF (Word converts it).
- Go to Insert → Signature Line or insert an image of your signature.
- Export back to PDF via File → Export → Create PDF/XPS.
This works but may alter the PDF's formatting significantly.
Electronic Signature vs Digital Signature: What's the Difference?
These terms are often confused:
- Electronic signature (e-signature): Any electronic indication of agreement — a typed name, a drawn signature, clicking "I Agree," or an image of a signature. Simple and legally valid in most jurisdictions for everyday contracts.
- Digital signature: A cryptographic mechanism using public-key infrastructure (PKI). It provides mathematical proof that the document was signed by a specific person and has not been altered since signing. Required for highest-trust applications like government filings and financial transactions. Requires a Certificate Authority-issued certificate.
For most business contracts, invoices, and agreements, an e-signature is perfectly sufficient and legally binding under laws like the US E-SIGN Act (2000), EU eIDAS Regulation, and similar legislation in most countries.
When to Use a Dedicated E-Signature Service
For high-stakes documents where you need audit trails, timestamping, and third-party verification, consider paid services:
- DocuSign — industry standard, widely accepted in legal and real estate
- Adobe Sign — integrates with Acrobat workflow
- HelloSign (Dropbox Sign) — simple and affordable for small businesses
For routine contracts, employee forms, and internal approvals, the free browser-based tool is sufficient.
Frequently Asked Questions
How do I sign a PDF for free without printing?
Use PDFWonder's free Sign PDF tool. Type your name or initials, choose the page and position, and download the signed PDF. No printing, scanning, or account required. Everything runs in your browser.
Is a digitally typed signature legally valid?
In many countries, a typed electronic signature is legally valid for most contracts and agreements. Laws like the US E-SIGN Act and EU eIDAS Regulation recognise e-signatures. However, requirements vary by country and document type. For high-stakes legal documents, a dedicated e-signature service with audit trails (like DocuSign or Adobe Sign) is recommended.
What is the difference between an electronic signature and a digital signature?
An electronic signature (e-signature) is any electronic indication of intent to agree — typed name, drawn signature, or image. A digital signature is a cryptographic mechanism that provides authenticity and non-repudiation, verified by a Certificate Authority. Digital signatures are more secure but require specialised software and certificates.
How do I sign a PDF on iPhone or Android for free?
Use PDFWonder's Sign PDF tool directly in your mobile browser (Safari or Chrome). It works the same on mobile as on desktop. Alternatively, Apple's Markup feature in iOS lets you draw a signature on a PDF in the Files or Mail app.
Can I add a drawn signature (not typed) to a PDF?
PDFWonder's current Sign PDF tool supports typed signatures. For drawn signatures, use Adobe Acrobat Reader's free mobile app, which lets you draw a signature with your finger or stylus.
How do I sign a PDF in Adobe Acrobat Reader for free?
Open the PDF in Acrobat Reader (free) → click "Fill & Sign" in the toolbar → click the signature tool → choose "Add Signature" → draw, type, or import an image of your signature → click Apply and place it on the document.