# Why You Can’t Highlight Text in a PDF: Common Issues and Easy Fixes

URL: https://pdf.net/blog/cant-highlight-text-in-pdf
Published: 2026-07-02
Author: Marcus Cooper
Reading time: 7 min
Categories: Edit PDF

> Can't highlight text in a PDF? Discover the common causes, such as scanned documents, restrictions, and conversion errors, along with the best fixes.

If you can't highlight text in a PDF, the document may contain scanned images, restricted permissions, conversion errors, or other issues that prevent text selection and annotation. This can make it difficult to review documents, add comments, and collaborate with others.

In this guide, we’ll show you how to identify the cause of the problem and apply the most effective solutions. We’ll cover how to check whether a PDF contains selectable text, common reasons highlighting does not work, practical fixes for each issue, and tips to prevent text-selection problems in future PDFs.

## Key Takeaways

- You can check whether a PDF has selectable text by attempting to highlight text or searching for words within the document.
- Common fixes include running OCR on scanned PDFs, removing document restrictions, reconverting the file properly, and trying a different PDF reader.
- Additional solutions include turning off read-only mode, updating your PDF software, repairing a corrupted PDF, and verifying that the content is not image-based.
- You can prevent future highlighting issues by reviewing PDFs before sharing, maintaining consistent PDF creation practices, and ensuring documents are configured for text selection and annotation when needed.

## How to Check If Your PDF Has Selectable Text

A quick way to check whether your PDF contains selectable text is to open the file and try highlighting a few words with your cursor. **If you can select**,** copy**, and** paste the text into another document**, the PDF contains selectable text.

You can also **use Ctrl+F or Cmd+F **and search for a word that appears in the document. If you can find matching text using this function, the [PDF is searchable](https://pdf.net/blog/how-to-make-pdfs-searchable) and text-based. On the other hand, if the text can’t be highlighted, copied, or searched, your PDF may not contain selectable text and could be a scanned image.

![How to Check If Your PDF Has Selectable Text](https://cdn.sanity.io/images/i16te7yp/production/11df62f8dfe6bca9b49d38d46a8b0048b3e4cf3f-1888x891.png?fit=max&auto=format)

## 7 Fixes for Not Being Able to Highlight Text in a PDF Document

If you can’t highlight text in a PDF, the file may be a scanned image, protected by security settings, opened in the wrong viewing mode, or corrupted. That said, let’s examine the seven most common fixes in case you can’t highlight text in a PDF.

### #1. Convert Scanned PDF to Editable Text (OCR Solution)

One of the most common reasons you can’t highlight text is** **a** scanned PDF**.** **While the document looks like it contains text, the words are stored as pixels rather than searchable characters, making text selection impossible.

The fix is to **run Optical Character Recognition (OCR) **on the file. [OCR technology](https://www.ibm.com/think/topics/optical-character-recognition) analyzes the scanned pages and converts the visible text into machine-readable characters. Once processing is complete, you can search, copy, and highlight content normally.

If you need to enable text selection in a PDF, apply OCR since it’s usually the most effective solution. After conversion, [save the new PDF](https://pdf.net/blog/how-to-save-as-a-pdf) and test if the text can be selected and copied.

### #2. Remove PDF Restrictions

In some cases, you can’t highlight text due to** PDF security settings**, which can block highlighting in two ways. Some documents require a password just to open, while others can be opened freely but have [permission restrictions](https://pdf.net/blog/how-to-change-pdf-permissions) that prevent content selection or annotation.

If you can open the PDF but can't highlight, the issue is a permission restriction. Check whether the document has permission restrictions that block annotations or text selection. If the document requires a password to open, you can use our [_Unlock PDF_](https://pdf.net/unlock-pdf) tool. Here’s how to do it step by step:

1. Go to our unlock tool and upload your PDF or use the drag-and-drop option.  
![Go to our unlock tool and upload your PDF](https://cdn.sanity.io/images/i16te7yp/production/6733cb5820dca2b7facc3a9295293ce4c06869d3-1879x823.png?fit=max&auto=format)
2. Enter the correct key and click** _Remove the password_**.  
![Enter the correct key and click Remove the password](https://cdn.sanity.io/images/i16te7yp/production/fee5d30a97b45bdc2868c5046324f5a032f54a92-1909x798.png?fit=max&auto=format)
3. Wait for the tool to remove the password and click **_Continue_**.  
![Wait for the tool to remove the password and click Continue](https://cdn.sanity.io/images/i16te7yp/production/cad50b1faa5ac5661fc82fa1253aa1a6881805b4-1873x801.png?fit=max&auto=format)
4. Once you gain access,** **try [highlighting the text](https://pdf.net/blog/how-to-highlight-text-in-pdf) again.  
![Once you gain access, try highlighting the text again](https://cdn.sanity.io/images/i16te7yp/production/1c54321455e4caa4cc82a13e3e15077755319b0a-1896x781.png?fit=max&auto=format)

### #3. Reconvert the PDF Properly

Sometimes, the issue is not with the PDF viewer or document permissions but with **the way the PDF was created**.** **Poor conversion settings can flatten text into images, corrupt text layers, or create formatting issues that prevent highlighting from working correctly.

To fix this, return to the original file and **convert it to PDF again**. Make sure the conversion process preserves the document's text layer rather than saving each page as an image. You can achieve this with one of pdf.net’s online converters.

For example, if you made your PDF from an original Word file, you can use our [**Word to PDF converter**](https://pdf.net/word-to-pdf) to recreate it. Here are the steps to follow:

1. Open the converter and upload or drag-and-drop your Word document.  
![Can't highlight text in PDF - Reconvert the PDF Properly](https://cdn.sanity.io/images/i16te7yp/production/b7d58d78113a7673fa659c63035820463407cad6-1891x760.png?fit=max&auto=format)
2. Wait for the conversion to finish and click **_Download PDF_**.  
![Wait for the conversion to finish and click Download PDF](https://cdn.sanity.io/images/i16te7yp/production/30d35b384eda6ea3de2103d7a0492dfcb1c1fd5b-1879x774.png?fit=max&auto=format)

### #4. Try a Different PDF Reader

Some **browsers** and **basic PDF readers have limited support** for text selection, [annotations](https://pdf.net/annotate-pdf), or highlighting features, which can make it seem as though the PDF is not working correctly.

If you're viewing PDFs directly in a browser tab, downloading the file and opening it in a dedicated [PDF reader](https://pdf.net/blog/best-pdf-readers) is a quick fix. A more [feature-rich PDF editor](https://pdf.net/change-text-in-pdf) may recognize the document's text layer and provide better support.

If you can't select text in your PDF using one reader but the same file works in another, the issue is likely software-related** **rather than a problem with the PDF itself.

### #5. Turn Off Read-Only Mode

If you can’t copy text from PDFs that appear normal,** **[read-only mode](https://pdf.net/blog/how-to-make-a-pdf-read-only) may be the cause. When this mode is enabled, **highlighting tools may appear unavailable** even though the document contains selectable text.

This mode is often [enabled for security reasons](https://www.lenovo.com/us/en/glossary/read-only/?srsltid=AfmBOopX-hiZ_DRemEqSZ2074CigImFXlfxydL7GXhVcl-D3J42cRnyF). For example, PDFs downloaded from the Internet, received as email attachments, or distributed by organizations may open in a protected mode to prevent unauthorized changes or potentially harmful content from running within the file.

Check your PDF reader for options such as "Read-Only," "Protected View," or similar security settings. If you have permission to modify the document, **switch to a standard viewing or editing mode and reopen the file. **Once the restriction is disabled, try selecting and highlighting text again.

![Can't highlight text in pdf - Turn Off Read-Only Mode](https://cdn.sanity.io/images/i16te7yp/production/af1e350418df572cb5c11eba00897363b960bee5-397x506.png?fit=max&auto=format)

### #6. Update Your PDF Software

Outdated PDF software can sometimes cause highlighting tools to malfunction. Older versions might have bugs, compatibility issues, or limited support for newer [PDF standards](https://pdfa.org/pdf-standards/), making it difficult to interact with certain documents.

Check whether an update is available for your PDF reader or editor and **install the latest version. **Software updates often include bug fixes and improvements related to annotations, text recognition, and document rendering. After updating, **reopen the PDF **and** test **whether you can highlight text normally.

### #7. Repair Your Corrupted PDF File

A damaged or partially corrupted PDF can **prevent text from displaying or functioning correctly. **Even if the document appears normal at first glance, issues within the file structure may interfere with text highlighting tools.

Try downloading the PDF again, requesting a new copy from the sender, or opening a backup version if one is available. You can also use a **PDF repair tool **to rebuild the file structure. Once the repaired PDF is saved, test whether text can be highlighted.

## How to Prevent This Issue in the Future

To avoid future issues with PDF text selection and annotation, keep these six tips in mind:

1. **Test text selection**. After creating a PDF, try selecting and highlighting a few lines of text. Catching a problem early is much easier than troubleshooting it after the file has been distributed.
2. **Keep scanned and digital PDFs organized separately**. [Scanned PDFs](https://pdf.net/blog/how-to-edit-scanned-pdfs) are more likely to experience text-selection issues than text-based ones. Knowing which files originated from a scanner can help you apply OCR before problems arise.
3. **Review PDFs after major edits or conversions**. Text layers can sometimes be affected when documents are merged, compressed, exported, or converted between formats. A quick review helps confirm that highlighting and text selection still work as expected.
4. **Establish PDF standards across your organization**. If multiple people create and [share PDFs](https://pdf.net/share-pdf), use consistent tools and export settings. This reduces the risk of generating files with incompatible formatting or missing text layers.
5. **Keep original source files accessible**. Retaining the original Word, PowerPoint, or design file makes it easier to [recreate a PDF](https://pdf.net/blog/how-do-i-make-a-pdf-file) if text-selection problems are discovered later. It also reduces reliance on editing or repairing the PDF itself.
6. **Periodically review archived PDFs**. Documents that are stored for long periods may eventually be accessed by new software or users with different needs. Checking important files occasionally helps ensure they remain searchable, selectable, and ready for annotation.

## Make PDFs Searchable, Selectable, and Easy to Annotate

![Make PDFs Searchable, Selectable, and Easy to Annotate](https://cdn.sanity.io/images/i16te7yp/production/a851d4aea4e8883447d89f6df9b700cd8f5c6602-1898x848.png?fit=max&auto=format)

Convert scanned PDFs into searchable text, create properly formatted PDFs, and prepare documents for highlighting, commenting, and collaboration with pdf.net.

All file transfers are protected with [HTTPS encryption](https://www.cloudflare.com/learning/ssl/what-is-https/) to keep your documents safe. Spend less time troubleshooting PDF text-selection issues and more time getting the work done.

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## Final Thoughts

If you can’t highlight text in a PDF, the issue is usually caused by scanned content, document restrictions, conversion errors, software limitations, or file corruption. Fortunately, most of these problems can be resolved without recreating the document from scratch.

Start by identifying whether the PDF contains selectable text, then work through the relevant fixes until highlighting functionality is restored. Taking a few preventive steps when creating, sharing, and managing PDFs can also help you avoid similar issues in the future. With the right tool, like pdf.net, your PDFs can remain searchable, selectable, and easy to annotate.

## Can’t Highlight Text in a PDF FAQs

### #1. How do I enable text selection in a PDF?

To enable text selection in your PDF, first determine whether the document contains actual text. If the file is image-based, **apply OCR** to create a searchable text layer. You should also **check for security restrictions** that may prevent text selection.

### #2. Can all PDFs be made editable?

Not all PDFs can be made editable without preprocessing. Some files contain scanned images, restricted permissions, or flattened content that must be processed first. In these cases, **OCR**, **access control**, or** reconversion **can make the PDF editable.

### #3. How to unlock a PDF for highlighting?

To unlock a PDF for highlighting, review the document's security settings and determine whether annotations or text selection are restricted. If you have authorization from the document owner, you can **remove or adjust permissions **to restore highlighting functionality.