Home » Tech » Error Fix – Can’t Highlight PDF in Adobe Reader Problem

Error Fix – Can’t Highlight PDF in Adobe Reader Problem

Published By Siddharth
Aswin Vijayan
Approved By Aswin Vijayan
Published On November 5th, 2022
Reading Time 5 Minutes Reading

A PDF file is one of the most popular portable document formats that is developed by Adobe. It is a platform-independent document that can be carried anywhere. However, a PDF file is able to save texts, images, graphics, hyperlinks, etc. and it can be viewed and printed on any platform. It is also able to add password protection, highlight, and comments. PDF files may contain lengthy documents that are difficult to read. So, with the help of the highlight feature of Adobe Reader, users can organize their notes and make it easier to find crucial information. But, sometimes we have noticed that many people can’t highlight PDF in Adobe Reader due to many reasons.

User Query: “I am reviewing a magazine that is downloaded in PDF file format. I want to highlight some important lines in it. But, I have found that the Adobe Acrobat highlight tool not working. It does not give me permission to highlight text in PDF files. Does anyone know how to enable the highlight option in Adobe Reader?”

Why Users Can’t Highlight PDF in Adobe Reader?

adobe acrobat highlight tool not working

There are many situations where users are unable to highlight text in PDF or add comments on it. Some of the most common cases are discussed below:

(a) A Scanned PDF document containing no real text: When Adobe acrobat highlight tool is not working, then it is possible that your PDF file is likely a scanned file that containing no any real text.

(b) Secured or protected document: The security settings of the PDF document clearly restrict you to add the comment on PDF document. In this setting, the author or distributor of the PDF-file does not allow you to add comments to it.

(c) Encrypted PDF document: If some security settings such as password or certificate are added on a PDF file, then the PDF document becomes encrypted, which restrict to make any changes on PDF file. Thus, users can’t highlight PDF in Adobe reader to encrypted PDF documents.

enable highlight option in adobe reader

How to Enable Highlight Option in Adobe Reader?

Two methods can be followed when the Adobe Acrobat highlight tool is not working. These are:

  1. Online method
  2. Offline method

Online Solution: When users can’t highlight PDF in Adobe Reader they can use an online solution. There are several online methods available but most of the tools have various limitations, so these are not widely used. The online methods work fine, but these are inaccessible in case of poor or unstable internet connection. Takes a long time to remove security and enable highlighting in PDF, which may result in data loss. With the help of an online solution, you can work with only one PDF file at a time. The main problem with online tools is that you have to upload your confidential or crucial data on the server. It is a quite risky task as there are chances of a data hack.

Offline Solution: As it is discussed above, there are many limitations with online tools. Thus, to overcome all these problems, users are looking for a reliable solution. Moreover, sometimes users don’t know how to enable highlight options in Adobe Reader either because of technical issues or due to any other reason. Therefore, to deal with such problems, one can use PDF Security Unlock software. It is a simple and reliable application that is available on the internet and can be easily installed on your system.

This tool is very useful to fix the issue can’t highlight PDF in Adobe Reader. By this utility, users can remove restrictions from PDF which helps them to add comments and highlight text on the PDF. This offline software is compatible to work with both Windows and Mac platform.

Advantages Integrated with this Application And Its Features

  1. Allows to save or print unlocked PDF files.
  2. Gives option to keep the source PDF file password in the output file.
  3. Support to remove 128 / 256 bit encryption from PDF.
  4. Compatible with different versions of PDF files created by different versions of Adobe Acrobat.

Guided Instructions to Unlock and Eliminate the Issue “Cannot Highlight Text in PDF”

Now, in order to enable highlight text in PDF documents follow the below steps:

  • At first, install and run the software to solve the issue “unable to highlight text in PDF.


  • Then, add PDF files to the software for eliminating the restrictions from it.

add files

  • Now, click on the Change button and select the destination location.


  • Finally, click on Unlock button & enable highlight text in PDF.


  • Finally, the software will display the process completion message.

completion message

By following these above steps the user can successfully enable the permissions to highlight secured PDF files And get rid of the issue of “cannot highlight text in PDF”.

Also Read: How to Enable PDF Annotations / PDF Markup Tools Instantly

Wrapping Up

In this blog, we have discussed how to enable highlight option in Adobe Reader. Along with these reasons due to which users can’t highlight PDF in Adobe Reader is also covered. We have also mentioned both online and offline solutions which can be easily used when the user is unable to highlight text in PDF. As, online tools have some limitations, so we recommend to use an effective professional tool for enabling the permissions to highlight secured PDF file.