The three ways to sign a PDF, and which one fits your situation
You can add your signature to a PDF in three ways: draw it directly in the document using free software, insert an image of your signature, or use a dedicated signing tool that creates a legally recognized digital signature. The method you choose depends on whether you need the signature to be legally binding, how formal the document is, and whether the other person needs proof that you signed it on a specific date.
For casual documents — a marked-up draft, a permission slip, a form you're sending to a friend — drawing or inserting an image works fine. For contracts, loan documents, or anything that might end up in court, you want a digital signature tool that creates a timestamped record. The difference matters because a drawn signature proves nothing about when you signed or that you actually did it. A digital signature does.
Key Takeaways
- Free PDF readers like Adobe Reader and Preview (on Mac) let you draw a signature directly onto a PDF without installing anything extra.
- If you want to reuse the same signature across many documents, create an image file of your handwritten signature and insert it as a picture instead of drawing each time.
- For legally binding documents, use a dedicated signing service like DocuSign, HelloSign, or Adobe Sign, which creates a timestamped record that proves when and by whom the document was signed.
- Drawing a signature or inserting an image is free but creates no legal proof of when you signed; digital signature tools cost money but are required for contracts and official documents.
Drawing your signature directly in Adobe Reader or Preview
The fastest way to sign a casual PDF is to open it in Adobe Reader (free, available on Windows and Mac) or Preview (built into Mac). Both let you draw a signature using your trackpad or mouse, and neither requires you to create an account or pay anything.
In Adobe Reader, open the PDF, click the "Fill & Sign" button on the right side, then click "Sign" and choose "Add Signature". You'll see a box where you can draw with your mouse or trackpad. Once you're happy with it, click "explore" and it appears on the page. You can move it around, resize it, and place it anywhere you need. When you're done, save the file — Adobe Reader will prompt you to save a copy with your changes.
On Mac, open the PDF in Preview, click "Tools" in the menu bar, then "Annotate", then "Signature". If you haven't created a signature in Preview before, it will ask you to draw one using your trackpad. After that, you can click the signature tool again and your saved signature appears — just click where you want to place it on the page. Save the file when you're finished.
The downside: these signatures are not legally binding. Anyone could claim you didn't actually sign it, and there's no timestamp proving when you did. For a lease, a contract, or anything that might be disputed later, this method is not enough.
Creating a signature image to reuse across documents
If you sign many PDFs, drawing the same signature over and over wastes time. Instead, create one signature image and insert it into every document you need to sign.
Start by signing a blank piece of paper with a pen, then photograph or scan it with your phone or scanner. Crop the image so it shows only your signature with a small border of white space around it. Save it as a JPG or PNG file on your computer. Now, whenever you need to sign a PDF, open the document in Adobe Reader or Preview and use the "Insert Image" or "Insert Picture" option to place your signature image where it needs to go. You can resize it to match the size of other signatures on the page.
This method is faster than drawing each time, and it looks more consistent across documents. Like drawing, though, it creates no legal proof of when you signed or that you actually did it. Use it for drafts, informal agreements, and documents where both parties trust each other.
Using a digital signature tool for contracts and official documents
When a document matters — a lease, a loan process, a contract, anything that could end up in court — use a digital signature service. These tools create a legally recognized signature that includes a timestamp, proof of identity, and a record of exactly when you signed. If someone later claims you didn't sign or signed on a different date, the service can prove otherwise.
The most common services are DocuSign, HelloSign (owned by Dropbox), and Adobe Sign. All three work the same way: you upload the PDF, specify where signatures go, and send it to whoever needs to sign. Each person signs using their own account, and the service records the date, time, and IP address of each signature. When everyone is done, you get a final PDF with all signatures and a certificate of completion attached.
These services cost money — DocuSign and Adobe Sign charge per signature or per month, and HelloSign has a free tier for up to three documents per month. If you only sign a few documents a year, the free tier might be enough. If you sign regularly, a monthly subscription makes sense.
Many banks, landlords, and government offices now require digital signatures for official documents. If the other party asks you to sign through DocuSign or a similar service, use it — they've chosen that method specifically because it creates legal proof.
What happens after you sign: saving and sharing the file
After you add your signature, save the file when ready. In Adobe Reader, use "File" then "Save a Copy" to keep the original and save a signed version. In Preview, use "File" then "Save" or "Export as PDF". If you used a digital signature service, the service handles saving and sends you a copy automatically.
Before you send the signed PDF to someone else, open it one more time to make sure the signature is in the right place and fully visible. A signature that's cut off at the edge of the page or hidden behind text creates confusion and may not be accepted.
If you're sending the file by email, keep the file name straightforward and include your name — something like "Lease_Agreement_Signed_Jane_Smith.pdf" tells the recipient when ready what they're looking at. If the document is going into a formal process (a loan process, a court filing), ask the recipient what format they need and whether they want the original file or a printed and scanned copy.
When to use each method: a quick decision guide
| Type of Document | Use This Method | Why |
|---|---|---|
| Draft, feedback, informal agreement | Draw in Adobe Reader or Preview | Free, fast, no account needed |
| Multiple similar documents | Signature image inserted each time | Faster than drawing, looks consistent |
| Lease, contract, loan, official form | Digital signature service (DocuSign, HelloSign, Adobe Sign) | Creates legal proof of when and by whom you signed |
| Document the other party sent through a signing service | Use that same service | They chose it for a reason; using it ensures compatibility |
Common problems and how to fix them
Your signature looks shaky or uneven. You're using a trackpad or mouse, which is hard to control. Try using a stylus if you have one, or draw more slowly. If it still looks bad, sign a piece of paper by hand, photograph it, and insert the image instead — it will look much cleaner.
The signature is too small or too large on the page. After you place it, click and drag the corners to resize it. Make it large enough to be clearly visible but not so large that it dominates the page. A signature should be roughly the size of your actual handwritten signature.
You signed the wrong version of the document. If you used a digital signature service, contact the service when ready — some allow you to void a signature and start over. If you drew the signature yourself, delete it (right-click and select "Delete"), save the file, and start again. Never send a document you signed by mistake; ask the sender for a corrected version.
The other person says they can't open your signed PDF. Save it as a standard PDF, not a special format. In Adobe Reader, use "File" then "Save a Copy" and make sure it says "PDF" in the file type dropdown. If they still can't open it, try exporting it again or converting it using a free tool like Smallpdf or ILovePDF.
Frequently Asked Questions
Is a signature I draw in Adobe Reader legally valid?
It depends on the context and the other party's agreement. A drawn signature is not legally binding on its own because it creates no proof of when you signed or that you actually did it. For casual documents both parties trust each other on, it's fine. For contracts, leases, or anything that might be disputed, use a digital signature service instead.
Can I use the same signature image in every PDF I sign?
Yes. Create one image of your signature, save it as a JPG or PNG file, and insert it into any PDF using the "Insert Image" option in Adobe Reader or Preview. This is faster than drawing each time and looks consistent, but it still creates no legal proof of when you signed.
What's the difference between a digital signature and a drawn signature?
A digital signature (created through DocuSign, HelloSign, or Adobe Sign) includes a timestamp, proof of identity, and a record of when and where you signed. A drawn signature or signature image is just a picture — anyone could claim you didn't actually sign it. Digital signatures are legally recognized; drawn ones are not.
Do I need to pay for a digital signature service?
HelloSign offers a free tier for up to three documents per month. DocuSign and Adobe Sign charge per signature or per month. If you sign documents rarely, the free tier is enough. If you sign regularly, a monthly subscription is cheaper than paying per signature.
What if the person asking me to sign wants me to use a specific service?
Use that service. They chose it for a reason — usually because it's what their business or legal process requires. Using the same service ensures the document will be compatible with their system and that the signature will be recognized as valid.