How to Insert Digital Signature in PDF

Last updated on October 8, 2019 by Bryan

PDF documents are often used by companies and even individuals for different transactions. The reason is that PDF files are more secured and can’t be tampered or altered easily. In any transaction, the signature of both parties is needed for verification and to finalize an agreement. In the past, to have someone sign documents, they must meet face to face and have each other sign the papers. However, with the advent of PDF files, people can add electronic signature to PDF and then send the signed PDF, making it easier and more convenient. When talking about digital signatures, we are not talking about a “printed” name, but a “cursive” signature. To learn how to insert digital signature in PDF, read the list of methods below.

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AceThinker PDF Writer

AceThinker PDF Writer is a tool that can add signature to PDF document. The tool also has other functions since it is an all-in-one PDF editor. Aside from being able to sign PDF documents, AceThinker PDF Writer can also edit the text contents of a PDF document. It can even convert PDF into other file formats, making it a versatile tool. These are just some of the essential features that the tool possesses. To learn how to use AceThinker PDF Writer to esign PDF, follow the steps below.

Step1 Install AceThinker PDF Writer

To launch the tool and start working on PDF documents, click one of the download buttons below depending on the operating system. Then run the installer and follow the instructions of the setup wizard. Make sure to follow the instructions correctly to avoid installation errors later on.

Try It for Free

Step2 Add the signature to the PDF

Once the tool is installed, immediately use it to open the PDF document. From the main interface, click the “Sign” and then select “Place Signature.” From the “Sign as” menu, select “New ID” and then enter the information that will be used to sign the PDF.

sign the pdf

Step3 Sign and save the PDF

If the PDF is password protected, then enter it on the space provided. Once all settings are done, click the “Sign” button and the signature will be inserted to the PDF document. Save the signed PDF after by clicking the “File” tab and selecting “Save” to apply the changes that were made.

save the pdf


Another tool that people can use to insert signature on PDF documents is LightPDF. This is an online PDF editor that can compete with pay-to-use editors. One of the many functions that one can do on LightPDF is inserting a signature. The tool is very handy; however, it cannot function without a stable internet connection in the area. This is the major drawback of using online editors, but if the internet in the area is strong and stable then there will be no issue. To learn how to use LightPDF to electronically sign PDF, follow the steps here.

create signature

How to use LightPDF

  • Launch LightPDF by clicking the link here.
  • From the homepage that will appear, click the “Add” button and select the PDF that needs to be signed, then upload it.
  • Once the PDF is uploaded, select the page where to add the signature.
  • After that, click the “Feather” icon and select “Create Signature.” This way, the user will be able to choose the form of a signature that they will insert.
  • From the option that will appear, select “Draw Signature.” to apply a more natural cursive signature.On the other hand, if there is an image of the signature or a certificate that is saved on the PC, select the other two options.
  • On the box that will appear, hover the mouse to write the signature. There is an option to change the color of the ink just above the box. Once done providing the signature, click the “Save” button.
  • The signature will be placed after clicking the “Save” button.
  • To save the the signature on the PDF page, click the “Save” icon. Once done, the file will be ready to download on the PC and click the download button.

save the signature

Add signature using Mac Trackpad

Adding a signature on a Mac device is also possible using its built-in PDF viewer, which is “Preview.” This tool allows Mac users to view, edit, and add signatures on PDF documents. Preview is an image and PDF viewer in one, making it a versatile tool on its own. However, Preview can only make basic PDF editing since it is originally intended as a viewer. Luckily, one function that is included among its editing options is the ability to add electronic signature to PDF using the Trackpad. To learn how to do this method, follow the steps below.

launch the preview

Quick Guide

  • From the “Finder,” go to the “Application” section and then type in “Preview” from the search bar of the tool and open it.
  • From the main interface, click the “File” tab and then select “Open” then look for the PDF document to sign.
  • From the main panel, click the “Tools” icon and then select the “Signature” option.
  • From the window that will appear, click “Trackpad” and select “Click here to begin.”
  • Use the “Trackpad” of the Mac to write the signature and then press any key from the keyboard to stop.
  • Click the “Done” button to insert the signature to the PDF page.
  • After placing the signature to its right place, save the PDF by clicking the “File” tab, and then choose “Save.”
  • The save box will then appear where information about the file like its “File name” must be provided. To apply all the information to the file, click the “Save” button.

save the file

Digitally sign PDF using Mac Camera

If the Trackpad is not working, there is an alternative that can be used, and that is by using the Camera of the Mac device. The process in inserting a signature on PDF using the Camera is straightforward. Like the previous method, it requires using the Preview and its editing functions. To learn how to insert digital signature in PDF using the Camera, follow these steps.

detect signature

Quick Guide

  • To launch the PDF on Preview, click the “Finder” tool from the dock, then go to the “Application” section.
  • From there, use the search bar to locate Preview faster.
  • Click the “File” tab from the taskbar and then select “Open” and search for the PDF file and open it on Preview.
  • Write the signature on a piece of white paper, then click the “Tools” icon from the main interface.
  • From the options that will appear, click the “Signature” icon and select “Camera” as the mode.
  • Place the paper in front of the camera and then let it detect the signature. Once finished, click the done button from the signature tool.
  • Drag the signature in place then save it on the PDF. To do so, click “File” from the taskbar and then select the “Save” option.
  • Enter the information required on the box that will appear and click the “Save” button to finalize the saving process.

save pdf signature


Inserting a signature on a PDF is not easy because a PDF file is known for its security features. However, with the right PDF tools adding these signatures is as easy as counting one two, and three. Using Acethinker PDF Writer as an example, with its premium features and efficiency, people will be able to insert signatures easily on any PDF. With its highly-intuitive interface, anyone with or without experience using PDF editors will surely get the hang of using it in no time. Truly an exceptional tool, Acethinker PDF Writer is indeed an excellent tool to have.

acethinker pdf writer

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Category - Edit PDF Doc

How to Insert Digital Signature in PDF

May 30, 2019

Post By Bryan to PDF Writer

Last updated on October 8, 2019

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