How to Digitally Sign PDF: 3 Solutions to Validate Your PDF Docs

“Hi! My colleague wants me to digitally sign PDF files, but I don’t know how to do that. How can I create a digital sign and add it to some PDF documents?” As a friend of mine asked me this question, I realized that a lot of people out there are confused about digital signatures. Ideally, digital signatures are commonly used to validate documents by adding a unique digital certificate. This makes PDF documents more secure and harder to be tampered with. The good news is that there are several ways to digitally sign PDF documents out there. In this guide, I’m going to list 3 different ways to insert digital signature in PDF.

Method 1. PDFelement: Securely Add Digital Signatures to PDF Files

Digital signatures have become an evident part of PDF documents these days due to the extra layer of security they provide. To add a unique Digital ID to your PDF files, you can take the assistance of PDFelement. It allows us to protect our PDF documents by adding unique certificates to them. You can share the unique key anyone to maintain the authenticity of the documents.
  • PDFelement lets us create new Digital IDs for any user that can be saved in the application.
  • It also lets us import Digital IDs from any other file as well.
  • Users can easily add the digital signatures of their choice to the PDF and even change its placement or appearance.
  • Besides that, you can also use PDFelement to edit, create, annotate, protect, and convert PDF files as well.

To learn how to digitally sign PDF files using PDFelement, the following steps can be taken.

Step 1: Add your digital signature

Firstly, launch PDFelement on your system and open the PDF file that you wish to protect on it. Now, go to its Protect tab, click on the signature field, and click on the “New ID” option. From here, you can either import a Digital ID from any other file or create a new digital signature of your own.

Step 2: Digitally sign PDF files

Once you have added the digital signature to the application, go to Protect > Sign Document and fill in the required field. After adding your name and the certificate, just click on the “Sign” button to add the Digital ID.

Step 3: Place or Validate the Signature

If you want, you can change the appearance of the signature by visiting Protect > Place Signature. This will let you change the appearance and placement of the signature.

Additionally, you can also go to the Protect tab to further validate the signature before sharing the document.



Method 2. Nitro Pro: The Best Way to Digitally Sign PDF Files

If you are looking for a smart and hassle-free solution to digitally sign PDF document on the go, then Nitro Pro would be your best bet. It features a QuickSign solution that will let you electronically sign your documents without leaving its interface. Users can add their digital signatures, manage them, and insert them to multiple documents without any trouble.

  • With Nitro Pro, users can add their digital signatures and insert it to the PDF documents of their choice easily.
  • The application would add a digital certificate to your documents to make it more secure and protect it from any alterations.
  • Apart from adding digital signatures, you can also request, view, and validate digital certificates from others as well.
  • You can also integrate your documents with Nitro Cloud to access faster signatures on the go.
  • Besides adding and managing signatures, Nitro Pro can also help you edit PDF documents, convert them, create PDF files, and do so much more.

Here’s how you can use Nitro Pro to sign a pdf document digitally and manage your digital IDs. Ideally, you can create a dedicated form field for your digital signature or add your digital ID to a PDF.

Option 1: Create a digital signature form field

In order to apply digital signature to PDF, you need to first create a digital signature. To create a new digital signature form field, just open the PDF in the Nitro Pro application, and go to its Forms tab > Form Fields > Digital Signature.

You can just click and resize the rectangle anywhere you like in the PDF file to position your digital signature.

Now, go to the Signature Properties and enter your name and other fields that will add the digital signature to the application.

Option 2: Add a Digital ID to your PDF

For this, just open the PDF file with Nitro Pro and go to its Protect tab > Certify Document and click on the “Sign” arrow. This will display a list of the available signatures in the gallery that you can pick. To add a digital signature, you need to have a digital ID beforehand. As of now, Nitro Pro supports Windows Certificate Store and PKCS#12 digital ID file.

Now, just place the digital signature to the desired location in the PDF file and “lock” it. Once the file is locked, it can’t be edited or further signed by the user.


If you haven’t created a digital ID, then go to the Protect tab > Identification > My Digital ID and click “New”. This will launch a wizard to let you create a new digital ID. Additionally, you can also import and export digital IDs from here as well.

Method 2: Use Adobe Acrobat Pro DC to Sign Documents

If you use the Pro version of Adobe Acrobat DC, then you can put digital signature on PDF using its native features too. It has integrated the Adobe Sign feature that would let you add your electronic signatures to the document of your choice. Apart from using its form fill feature, users can also draw their signatures as well. Furthermore, the application can also be used to add signers and add the location where the other user is supposed to sign the file.

sign pdf adobe

While the application lets us add PDF digital signature verification, it does come at a heavy price tag and is often avoided by many users due to its complicated interface.

Method 3: Use Online Tools to Digitally Sign PDFs

There are also various services that you can try to create PDF digital signature online. You can just load your PDF file to these online tools and add digital signature in PDF file. Though, most of these online tools are either paid or would leave their watermark in the signed file. Nevertheless, you can simply look up on the web and use an online e-sign solution for PDF files. Some of these popular tools to digitally sign PDF online are from Soda PDF, Sejda, SmallPDF, LightPDF, PDFFiller, and so on.

sign pdf online smallpdf

This brings up to the end of this extensive guide on how to sign PDF with digital signature. As you can see, I have explored three different solutions to digital signatures for PDF documents  like a pro. Needless to say, the simplest solution of them all is Nitro Pro as it comes with so many features and lets us protect PDF files in no time. You can also use Nitro Pro to edit, convert, create, and manage PDF documents like a true professional as well.