Can't Highlight PDF? Get 6 Solutions Here

[Key Takeaways]: This article focuses on why you can’t highlight text in PDF and how to fix this issue. Additionally, the process of enabling highlighting text in PDF will be explained step by step.

Highlighter is an essential tool to mark up the key words, phrases, or sentences when taking notes on a PDF. The added highlights will catch readers’ eyes and help them concentrate on crucial points in the first instance. However, something gets wrong occasionally that you are unable to select or highlight text in PDF.

What factors contribute to the problem of can’t highlight PDF and how to enable highlighting text again in PDF? Read on to delve into the reasons and solutions.

Cisdem PDFMaster

Fix the Can’t Highlight PDF Issue in Various Scenarios

• Provide multiple annotation tools, highlights, underline, shapes, lines, stamps, etc.
• Customize the highlight color and opacity.
• OCR scanned PDF to enable text selection and highlighting.
• Convert PDF into many editable formats, like Word, Excel and PPT.
• Remove the editing permission password from PDF easily.
• Delete and add the digital signature as you need.
• Other robust tools: Edit PDF, Page Edit, Form, Redact, Page Display.

Free Download macOS 11 or later Free Download Windows 11/10/8/7
Earlier than macOS 11, click here

Why Can't I Highlight Text in PDF? Check 5 Reasons Below

There are various reasons that can cause the “can’t highlight PDF” issue, from the PDF itself to the PDF viewer you’re using. To figure out why you are unable to highlight text in PDF, check the following 5 reasons carefully.

Reason 1: The PDF is scanned or image-based.

A normal PDF typically contains the layers of text and images simultaneously, whereas the scanned or image-based PDF does not have a real layer of text. They are generated from scanning paper documents or composed of images. All the texts in these PDFs are displayed in the image layer, so you won’t be able to select, highlight or make any edits to the text anyway.

Reason 2: The PDF is encrypted with owner password.

Owner password, also known as permission password, is a type of password that sets restrictions on PDF to stop viewers from editing, copying, printing or annotating the content. If your PDF file is locked with password protection, the highlighter option in the PDF viewer will be grayed out. You can select the text successfully but can’t highlight it unless you enter the correct password or unlock the file.

Reason 3: A valid digital signature is inserted in the PDF.

When it comes to confidential files, the author usually adds a digital signature to verify the authority of the information and protect the file from being tampered with by others. Once the digital signature is successfully inserted into a PDF, no one can make changes to that file, including drawing highlights. Otherwise, editing a digitally-signed PDF will invalidate the signature.

Reason 4: The PDF is corrupted.

If your PDF was downloaded from an informal website and contains corruption, this may also prevent you from highlighting text in the PDF. In addition, if your computer program has been attacked or the file has been stored incorrectly for a long time, both of them might make the PDF not work normally. Try download the PDF file from the source again.

Reason 5: The PDF viewer is outdated and lacks the highlight functionality.

Besides the PDF file itself, the failure to highlight text in a PDF can also be caused by the PDF viewer you’re running. Software nowadays is updating in a fast speed and new functionalities are constantly coming out. Some PDF viewers are out of date and don’t have the capabilities of highlighting PDF. You’d better check your PDF viewer for updates or switch to another program.

Get a One-Stop Solution to Fix Can't Highlight PDF

Regardless of which reason, an all-embracing PDF editor can help you solve the problem of can’t highlight PDF at one stop, that is Cisdem PDFMaster. It is an AI-integrated software for all your PDF tasks on Windows and Mac, aiming to make users a real PDF master as its name suggests.

Why Pick Cisdem PDFMaster as the Top Solution to Fix Can’t Highlight PDF?

• It is packed with an advanced OCR capability that can convert scanned PDF files into searchable and editable PDF, Word, Excel, PowerPoint, etc.
• It can function as a PDF unlocker, getting rid of the permission password protection from the encrypted PDF documents, so you can make modifications like highlighting text to PDF.
• It provides multiple options to add an electronic signature and a digital signature. Removing the added signature is allowed as well.
• This PDF viewer offers various page display modes. To improve readability, it lets users draw highlight, underline, squiggly line, strikethrough and freehand.

What Else Can Cisdem PDFMaster Do Besides Highlighting PDF?

In addition to the above-mentioned advantages, Cisdem PDFMaster can do much more on PDF documents. The fabulous features include replacing and adding texts and images, creating and filling out PDF forms, measuring PDF, redacting the sensitive information, manipulating PDF pages, adding various elements to PDF, like shapes, links, background, header & footer, page numbers, stamps, etc.

Thanks to its built-in AI technology, it can also summarize, translate, proofread and rewrite the PDF content smartly.

How to Fix Can’t Highlight Text in PDF?

First and foremost, download and install Cisdem PDFMaster app on your computer.
. Free Download macOS 11 or later Free Download Windows 11/10/8/7
Earlier than macOS 11, click here

Solution 1: OCR Scanned PDF to Searchable

1. Run the program of Cisdem PDFMaster.
2. Scroll right the Quick Tools page and find the OCR tool.
3. Upload your scanned PDF file, an OCR dialog box will pop up where you can choose the page range, layout settings and OCR language.
4. Click OCR button in the middle, you can preview the OCR results in the right preview box. Save it as a searchable PDF.
5. Open the recognized PDF with Cisdem PDFMaster again.
6. Go to Tools tab, this software offers multiple annotation tools, hit Highlight icon and start highlighting the important points.
7. On the right-hand panel, you can adjust the color and opacity.

Solution 2: Unlock Password Protected PDF

1. Open the PDF you can’t highlight with Cisdem PDFMaster.
2. The program will prompt you that the PDF is protected by a permission password, click Decrypt if you know the correct password.
3. If not, select Editor feature, choose Remove Security from Security drop down list.
4. In the Remove Security dialog box, click Add Files to add this PDF again, here batch processing is allowed.
5. When the PDF is added successfully, click Remove Password and choose a directory to store the unlocked PDF.
6. Now you can highlight the text in this PDF without any difficulties.

Solution 3: Re-sign the PDF File

As for digitally-signed PDF file, it is much more difficult to fix the can’t highlight PDF issue, since any changes to PDF will make the inserted signature invalid. The only solution is to find the original document and add the signature again after highlighting the PDF.

1. Open the original PDF file in the PDFMaster app, or deleted the old signature in the program directly.
2. Now you are free to highlight the text in PDF.
3. Choose Sign feature > Create Signature Field, place the rectangle on the page you want.
4. Select Add Digital Signature and click on the inserted rectangle. A dialog box will prompt up, follow the guide to add a digital signature step by step.
5. Don’t forget to save the PDF file.

Enable Highlighting in PDF Using Different PDF Viewers

If your PDF is not scanned, protected or signed, you can try another PDF viewer to solve the problem of can’t highlight PDF. Some free programs also provide several annotation tools to highlight a PDF. Here are the tutorials on how to highlight in PDF using different PDF viewers.

Can't Highlight PDF in Adobe Reader?

Adobe Reader is the free version of Adobe Acrobat, developed by Adobe. The free service contains only basic features like adding comments, stamps and measuring objects. More advanced functionalities require a subscription.

How to Highlight Text in PDF Using Adobe Reader?

1. Launch the program of Adobe Reader.
2. Go to Menu drop-down list and open your PDF file with it.
3. Choose All tools > Add Comments, hit Highlight selected text icon in the floating menu.
4. Select the text to highlight, click on the highlight, you can change its color and delete it as per your requirements.
5. Go back to Menu > Save to apply the changes.

Can't Highlight PDF in Preview?

Preview is the default PDF and image viewer on macOS. While it's not as powerful as paid software, it's sufficient for simple PDF tasks. You can utilize it to highlight, underline and strike through the text as you need.

How to Highlight on PDF on Mac?

1. Open your PDF file with Preview app.
2. Click on the Highlights and Notes icon (pencil-like), you can change the highlight color from its drop-down menu.
3. Drag your cursor to select the text you want to highlight. It allows to remove the added highlight by right clicking.
4. Go to File > Save to highlight this PDF successfully.

Why Can't Select Text in PDF in Chrome?

A part of Google users are accustomed to viewing PDF files directly in Google Chrome browser, only to fail to find the highlight option. To be exact, Google Chrome doesn't have any features available other than printing PDFs. But you can complete this job with the help of Google Extensions, such as Weava Highlighter.

Steps to Highlight PDF in Google Chrome

1. In Google Chrome browser, expand 3-dot menu, choose Extensions > Visit Chrome Web Store.
2. Type “highlighter” in the search box, it will show various useful extensions. Here we take Weava Highlighter as an example, click Add to Chrome.
3. Download this extension and log into it with your Google account.
4. Hit on Extensions icon and pin Weava Highlighter on the top bar.
5. Drag a PDF file into Google Chrome and run Weava Highlighter to highlight the text.

Have you already fixed the issue of can’t highlight PDF after reading the whole post? If you have any new problems with highlighting text, please leave a comment below.