How to Add Your Signature to a PDF File

The fastest way to sign a PDF depends on what you already have

You can add a signature to a PDF in three main ways: draw one directly in your PDF reader, insert an image of your handwritten signature, or use your trackpad or mouse to create one on the spot. The method that works best depends on whether you have a scanner, a tablet, or just your computer keyboard and mouse.

Most people use either Adobe Acrobat Reader (the free version) or their web browser to sign PDFs, because both are already on your computer. If you need to sign many documents or want a signature that looks professional, you can create a digital signature file once and reuse it. This takes about five minutes to set up.

The document itself does not change based on how you sign it — a signature added with a mouse is just as legally valid as one drawn on a tablet, as long as you have the right software and the person receiving it accepts digital signatures.

Key Takeaways

Adobe Acrobat Reader's free version lets you draw, type, or insert a signature image directly into any PDF without installing extra software.
If you have a scanner, you can sign a printed copy by hand, scan it back in, and insert the image into your PDF in under two minutes.
Your web browser (Chrome, Safari, Firefox, Edge) can open and sign PDFs if you upload them to Google Drive, OneDrive, or similar cloud storage.
Once you create a signature file, you can save it and reuse it on future documents instead of drawing it each time.

Signing a PDF in Adobe Acrobat Reader on Windows or Mac

Open the PDF in Adobe Acrobat Reader (the free version you can download from adobe.com). Click the Fill & Sign button on the right side of the screen, or look for a pencil icon in the toolbar.

Click Sign and you will see three options: Draw (to draw with your mouse or trackpad), Type (to type your name in a signature font), or Image (to upload a photo of your handwritten signature). Choose the one that matches what you have. If you draw, use your trackpad or mouse to write your name in the box that appears. If you type, select a font style and your name will appear in that style. If you upload an image, click Image, find the file on your computer, and it will be placed where you clicked.

Once your signature appears on the page, you can resize it by dragging the corners, move it by dragging the center, or delete it and start over by clicking the X. When it looks right, click outside the signature box to finish. Save the file using File > Save or File > Save As if you want to keep the original unsigned version.

Creating a reusable signature from a scanned image

If you have a printer and scanner, this method gives you the most natural-looking signature. Sign a blank piece of paper with a pen, scan it into your computer as a JPG or PNG file, and then insert that image into your PDF. The scanned signature looks like your actual handwriting and you can use the same image file on every document you sign.

To scan your signature, use your scanner's software (usually installed when you plug in the scanner) or use your phone's camera and a free app like Adobe Scan or Microsoft Lens to photograph the signed paper. Save the file to your computer in a folder you will remember — something like "My Signatures" works well.

Open your PDF in Adobe Acrobat Reader, click Fill & Sign, then Sign, then Image. Find the signature file you just created and click Open. The signature will appear on your PDF at the size of the image. Resize and position it where you need it, then save the file.

Signing a PDF in your web browser

If you do not have Adobe Acrobat Reader installed, you can sign a PDF using Google Drive, Microsoft OneDrive, or your web browser's built-in tools. Upload your PDF to Google Drive or OneDrive, right-click the file, and select Open with > Google Docs (or the equivalent in OneDrive). The PDF will open as an editable document in your browser.

Click Insert > Drawing and select New. A drawing box will open where you can draw your signature with your mouse or trackpad. Click Save and Close when you are done. The signature will be placed on the page. You can then download the file back to your computer by clicking File > Download > PDF Document.

This method works on any computer with a web browser and internet connection, but the signature will be embedded as an image rather than as a true digital signature field. The document is still valid and signed — it just cannot be edited further without removing the signature.

Signing with a tablet or stylus

If you have an iPad, Android tablet, or a stylus connected to your computer, you can draw a signature that looks much more natural than one made with a mouse. Open the PDF in Adobe Acrobat Reader on your tablet or in a program like Notability or GoodNotes, tap or click the signature tool, and draw your name directly on the screen with your stylus or finger.

On a Windows computer with a stylus, open the PDF in Adobe Acrobat Reader, click Fill & Sign > Sign > Draw, and use your stylus to write in the box. The result will be smoother and more natural-looking than using a mouse.

If you are signing on a tablet and want to save the signature to reuse later, take a screenshot of just the signature, crop it to remove the background, and save it as an image file. Then use the Image method described above on future documents.

What to do if the PDF will not let you sign it

Some PDFs are locked or protected and will not allow you to add signatures or fill in fields. If you see a message that says the document is locked or restricted, the person who created it set permissions that prevent editing. You have two options: ask the sender to unlock the PDF and send you an unlocked version, or convert the PDF to a different format.

To convert a locked PDF, upload it to a free online converter like Smallpdf.com or IlovePDF.com, download the converted file, and then sign it using the methods above. This removes the protection but also means you cannot edit the original formatting — the signature will be added as an image on top of the existing document.

If the PDF is a form with specific signature fields (boxes marked "Sign here"), click directly in those boxes instead of drawing anywhere on the page. The signature will snap into the field automatically. If clicking in the field does nothing, the document is likely locked and you will need to ask for an unlocked version.

Saving and organizing your signed PDFs

After you sign a PDF, save it with a clear filename that includes the date and what the document is. Instead of "Document1.pdf", use something like "Lease_Agreement_2024_01_15.pdf" or "Tax_Return_Signed_2024.pdf". This makes it much easier to find the right version later if you need to refer back to it.

Create a folder on your computer called "Signed Documents" and keep all your signed PDFs there. If you sign documents regularly, add subfolders by year or by type (Contracts, Medical, Financial, etc.). This way, if someone asks for proof that you signed something, you know exactly where to find it.

If you created a reusable signature image file, keep that in a separate folder and do not delete it. You will use it again on future documents. Back up both your signed documents and your signature file to cloud storage (Google Drive, OneDrive, Dropbox) so you do not lose them if your computer fails.

Frequently Asked Questions

Is a digital signature legally valid?

Yes, in most countries including the United States, Canada, and the UK, a digital signature on a PDF is legally valid as long as both parties agreed to sign digitally. The method does not matter — drawn, typed, or image-based signatures all have the same legal weight. The person receiving the document must accept it as valid, which they almost always do for contracts, forms, and agreements.

Can I sign a PDF on my phone?

Yes. Download Adobe Acrobat Reader for iPhone or Android, open the PDF in the app, tap the pencil icon, and draw your signature. You can also use Google Drive or OneDrive on your phone to upload the PDF and sign it in your browser. The process is the same as on a computer, just with touch instead of a mouse.

What if I make a mistake while signing?

Click the undo button (usually a curved arrow) or press Ctrl+Z (Windows) or Command+Z (Mac) to remove the signature you just drew. You can then draw it again. If you already saved the file, open it, delete the signature, and save again. There is no limit to how many times you can redo it.

Can I use the same signature on multiple documents?

Yes. Create a signature image file once (by scanning your handwritten signature or drawing one in Adobe Acrobat Reader and saving it), then insert that same image into every PDF you sign. This is faster than drawing a new signature each time and keeps your signature consistent across all documents.

Do I need to buy Adobe Acrobat Pro to sign a PDF?

No. The free version of Adobe Acrobat Reader includes the Fill & Sign feature, which is all you need to add a signature to a PDF. Adobe Acrobat Pro (the paid version) adds advanced features like creating digital signature certificates, but for most people the free version is enough.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.