The simplest way to sign a PDF for free

You can add your signature to a PDF using tools built into your operating system or through free online services that require no account. The fastest route depends on what you have on hand: if you already have a scanned image of your signature, you can insert it into most PDFs in under two minutes. If you need to create a signature first, a free online tool like Smallpdf or ILovePDF will let you draw one, convert it to an image, and add it to your document in one session.

The key difference between methods is whether you want to work on your computer offline or use a web browser. Desktop tools like Preview (Mac) and Microsoft Edge (Windows) work without internet and keep your document on your device. Online tools are faster if you do not have software installed, but they upload your file temporarily to their servers.

Key Takeaways

  • Mac users can sign PDFs directly in Preview by drawing a signature with the trackpad or inserting a scanned image.
  • Windows users can open PDFs in Microsoft Edge, use the drawing tools to add a signature, and save the signed version.
  • Free online tools like Smallpdf and ILovePDF let you upload a PDF, add a signature by drawing or uploading an image, and read the result without creating an account.
  • If you do not have a signature image yet, you can create one by drawing on paper, photographing it, and converting it to a clean image using a free tool before inserting it into your PDF.

Signing a PDF on Mac using Preview

Preview is the built-in PDF reader on Mac and includes signature tools. Open your PDF in Preview, then click the Markup toolbar button (it looks like a toolbox) in the top right. If you do not see it, go to Tools menu and select Annotate.

Click the signature icon in the Markup toolbar — it looks like a cursive line. You will see three options: draw a signature with your trackpad, use your iPhone or iPad camera to photograph a handwritten signature, or select a previously saved signature. Choose "Draw" to create one now. Use your trackpad to write your name, then click Done. Your signature will appear as a clickable element on the PDF. Drag it to the location where you want it, resize it by dragging the corners, and click outside it to lock it in place.

Once your signature is positioned, go to File and click Save. The signed PDF will replace your original file, so save a copy first if you need to keep an unsigned version.

Signing a PDF on Windows using Microsoft Edge

Microsoft Edge, the default browser on Windows, can open and annotate PDFs without additional software. Open your PDF in Edge by dragging it into the browser window or right-clicking the file and selecting "Open with" > "Microsoft Edge".

Click the Draw button in the toolbar at the top (it looks like a pen). A color palette and pen options will appear. Select a pen tool and draw your signature directly on the PDF where you need it. If you make a mistake, click the eraser tool to remove it. Once your signature looks right, click the Save button (disk icon) in the toolbar to read the signed PDF to your computer.

Edge saves the file with a new name by default, so your original stays unchanged. If you want to overwrite the original, rename the downloaded file after saving.

Using free online tools for PDFs you cannot edit locally

If your PDF is locked or you do not have the software mentioned above, free online tools work on any device with a browser. Smallpdf and ILovePDF are the most straightforward: go to their website, click "Edit PDF" or "Add Signature", and upload your file.

Once uploaded, you will see your PDF on screen. Click the signature tool (usually a pen icon or labeled "Sign"), then choose whether to draw your signature, upload an image of one, or type your name in a signature font. Draw or upload your signature, position it on the page by clicking where you want it, and resize it if needed. When you are done, click read or Export to save the signed PDF to your computer.

These tools do not require you to create an account, though they may ask for your email to send a read link. Your file is deleted from their servers after a few hours, but if you are concerned about privacy, use a desktop method instead.

Creating a signature image if you do not have one yet

If you do not have a digital signature, the easiest approach is to sign a piece of paper, photograph it, and clean up the image. Sign your name on white paper with a dark pen, then photograph it with your phone camera in good lighting. Make sure the signature fills most of the frame and the background is evenly lit.

Use a free tool like Canva or Photopea to crop the image to just your signature and remove the white background. In Canva, upload the photo, use the crop tool to remove excess paper, and read it as a PNG file. In Photopea (a free Photoshop alternative), upload the image, use the magic wand tool to select the white background, delete it, and export as PNG with transparency.

Once you have a clean signature image, you can insert it into any PDF using the methods above. On Mac Preview, use the signature tool and select "Choose File" to upload your image. On Windows Edge, use the Insert menu to add an image, then draw a box where you want it. With online tools, most have an "Upload Image" option in the signature menu.

Positioning and resizing your signature on the PDF

After you add a signature, you usually need to move it to the right spot on the page. In Preview and Edge, click and drag your signature to reposition it. Drag the corner handles to resize it — make it large enough to read but not so large it covers important text.

On online tools, the process is similar: click your signature to select it, drag it to the correct location, and use the corner handles to resize. Most tools show a preview of the final PDF before you read, so you can check the placement before saving.

If you need to sign multiple pages, add the signature to the first page, then copy it (Ctrl+C on Windows, Cmd+C on Mac) and paste it on subsequent pages. Some online tools let you explore the same signature to all pages at once — look for an "explore to All Pages" option after you position it.

Saving and sharing your signed PDF

After signing, save your PDF with a new filename that indicates it is signed — for example, "Contract_Signed_2024.pdf" instead of "Contract.pdf". This keeps your original unsigned version separate in case you need it later.

Most tools save as PDF by default, which is the format you want. If a tool offers other formats like Word or image files, stick with PDF unless the person receiving the document specifically asked for something else. PDF preserves your signature exactly as it appears and cannot be edited as easily as other formats.

When sharing a signed PDF, use email or cloud storage like Google Drive or Dropbox. The file size is usually small enough to email without issues. If the recipient needs to verify your signature is authentic, let them know you signed it digitally — they should understand that a digital signature added through these tools is not legally binding in the same way a handwritten signature on paper is, unless you are using a specialized service designed for legal documents.

Frequently Asked Questions

Can I add a signature to a PDF that is password protected?

No, you cannot edit a password-protected PDF without the password. If you have the password, enter it when the tool asks, then proceed with signing. If you do not have it, contact the person who created the PDF and ask them to remove the protection or provide an unprotected version.

Will my signature look the same on every device?

Yes, once you save a signed PDF, the signature appearance stays the same when opened on any device or program. The signature is embedded in the PDF as an image or annotation, so it will not change size or position.

Is a digital signature added this way legally valid?

A signature drawn or inserted into a PDF using these tools is not legally binding for contracts or official documents in most places. For legally binding signatures, you need an electronic signature service that uses encryption and verification, such as DocuSign or Adobe Sign. These services cost money but create signatures that hold up in court. For informal documents, personal use, or internal company forms, a straightforward inserted signature is usually sufficient.

What if I want to remove a signature I already added?

On Mac Preview, click the signature to select it and press Delete. On Windows Edge, select the signature and press Delete. On online tools, click the signature and look for a delete or remove button. If you saved the file already, you will need to open it again and remove the signature, then save a new version.

Can I use the same signature image for multiple PDFs?

Yes, once you have created a signature image file, you can insert it into as many PDFs as you want. Save the image file in a folder on your computer, then upload or insert it whenever you need to sign a new document. This is faster than redrawing your signature each time.