Introduction: Why Highlighting PDFs Is Useful
Ever wanted to mark important points in a PDF just like you do in a physical book? Whether you’re studying, reviewing notes, or proofreading documents, highlighting is a simple yet powerful way to keep track of key information.
For students, highlighting helps with active learning, making it easier to recall important concepts. Professionals use it to review contracts, reports, or research papers, ensuring no crucial details are missed. Even casual readers find it useful for annotating e-books or articles for future reference.
The good news? You don’t need printed copies or highlighters! Digital tools make it easy to highlight PDFs on computers, tablets, and even smartphones. Whether you’re using Adobe Acrobat, free online tools, or mobile apps, there’s a method that fits your needs.
In this guide, we’ll walk you through:
✔ The best free and paid tools for highlighting PDFs
✔ Step-by-step instructions for desktop and mobile devices
✔ Pro tips to highlight efficiently without cluttering your document
Ready to level up your PDF game? Let’s dive in!
Can You Highlight Text in a PDF Online?
Yes, and it’s easier than you think! Whether you’re reviewing a report, studying notes, or proofreading a document, highlighting PDFs online is a quick and convenient way to mark important information—no downloads needed.
Two Types of PDF Highlighting
Before choosing a tool, it’s important to know what kind of PDF you’re working with:
1. Selectable Text PDFs:
- These are digital PDFs where you can click and copy text.
- Highlighting is simple—just select the text and apply the highlight color.
- Most online tools support this type of PDF.
2. Scanned PDFs (Image-Based):
- These are scanned documents or images saved as PDFs, meaning the text isn’t directly selectable.
- To highlight text, you’ll first need an OCR (Optical Character Recognition) tool to convert the image into editable text.
- Some tools offer built-in OCR, while others require a separate conversion step.
Best Online Tools for Highlighting PDFs
Here are some great free and paid tools for online highlighting:
✔ Smallpdf – Simple and user-friendly, works with both text-based and scanned PDFs (OCR available).
✔ Sejda PDF Editor – Allows direct highlighting without installation, but has free-use limits.
✔ ILovePDF – Integrates with cloud storage for easy access and marking.
✔ Adobe Acrobat Online – Professional features with a free version for basic highlighting.
With these tools, you can highlight PDFs online from any device—no software required! Up next, let’s see how to do it step by step.
How to Highlight Text in a PDF Online: Step-by-Step Guide
Highlighting text in PDFs has become increasingly accessible with various online tools, allowing users to annotate documents without the need for software installations. Here’s a step-by-step guide on how to highlight text in a PDF using some popular online platforms.
Using PDF4Sure (Free & Easy)
Note: As of my last update, specific details about PDF4Sure’s functionalities are limited. The following steps are based on standard features commonly found in online PDF editors.
1. Upload Your PDF:
- Navigate to the PDF4Sure website.
- Click on the “Upload” or “Choose File” button.
- Select the PDF document you wish to highlight from your device.
2. Select the Highlight Tool and Apply It:
- Once the PDF is uploaded, it should open in an editable viewer.
- Look for a “Highlight” tool, often represented by a marker icon.
- Click on the tool, then select the text you want to highlight.
- Some editors allow you to choose the highlight color; if available, pick your preferred shade.
3. Save and Download Your Highlighted File:
- After highlighting, find the “Save” or “Apply Changes” button.
- Once processed, a “Download” option should appear.
- Click to download the newly highlighted PDF to your device.
Using Smallpdf
Smallpdf offers a user-friendly interface for various PDF tasks, including highlighting.
1. Access the PDF Editor:
- Visit Smallpdf’s PDF Editor
2. Upload Your PDF:
- Click on “Choose File” or drag and drop your PDF into the designated area.
- You can also import files from cloud services like Google Drive or Dropbox.
3. Highlight Text:
- Once uploaded, the PDF will appear for editing.
- Select the highlighter icon from the toolbar.
- Choose your desired color and opacity.
- Click and drag over the text you wish to highlight.
4. Save and Download:
- After highlighting, click “Apply Changes.”
- Once processed, download the edited PDF to your device.
Features and Limitations of Smallpdf:
Pros:
- No installation required; entirely web-based.
- Supports various PDF editing tools beyond highlighting.
Cons:
- Free users are limited to a certain number of tasks per day.
- Batch processing and advanced features require a subscription.
Using Sejda PDF Editor
Sejda is another robust online PDF editor with highlighting capabilities.
1. Open Sejda PDF Editor:
- Navigate to Sejda’s PDF Editor:
2. Upload Your PDF:
- Click “Upload PDF file” and select your document.
- Alternatively, import from cloud storage services.
3. Highlight Text:
- With the PDF open, select the “Annotate” option.
- Choose the “Highlight” tool.
- Drag over the text you wish to emphasize.
4. Adjust Highlight Color and Thickness:
- Sejda allows customization of highlight color and thickness.
- Modify these settings as desired before or after applying the highlight.
5. Save and Download:
- Click “Apply Changes.”
- Once processed, download the updated PDF.
Features and Limitations of Sejda PDF Editor:
Pros:
- Offers a range of editing tools, including text editing and annotations.
- No sign-up required for basic features.
Cons:
- Free usage is limited to three tasks per hour.
- File size and page number restrictions apply for free users.
Using DocHub for Google Drive Users
DocHub integrates seamlessly with Google Drive, making it convenient for users who store documents there.
1. Access DocHub:
- Visit DocHub’s website.
2. Sign In and Integrate with Google Drive:
- Sign in using your Google account.
- Grant necessary permissions to access your Google Drive.
3. Open PDFs from Google Drive:
- In DocHub, click “New” and select “Import from Google Drive.”
- Choose the PDF you wish to edit.
4. Add Highlights:
- With the PDF open, select the highlighter tool from the toolbar.
- Choose your preferred color.
- Click and drag over the text to highlight.
5. Save and Sync:
- DocHub automatically saves changes.
- To ensure updates reflect in your Google Drive, click “Export” and choose “Export to Drive.”
Features and Limitations of DocHub:
Pros:
- Direct integration with Google Drive for easy access and saving.
- Supports various annotation tools, including signing and form filling.
Best Free Online PDF Highlighters
Finding the right tool to highlight PDFs online can make studying, reviewing, or editing documents much easier. Here are some of the best free online PDF highlighters, each offering unique features to fit different needs.
1. PDF4Sure – Fast and Simple Online Highlighting
If you need a quick, no-fuss way to highlight PDFs, PDF4Sure is a great option.
✔ Easy-to-use interface – Just upload your file, highlight text, and download.
✔ No watermarks – Your document remains clean after editing.
✔ Fast processing – Highlights apply instantly without lag.
Limitations:
✘ Lacks advanced annotation tools beyond highlighting.
✘ No OCR support for scanned PDFs.
2. Smallpdf – User-Friendly with Multiple PDF Tools
Smallpdf is a well-known online PDF editor that provides a simple yet powerful highlighting feature.
✔ Drag-and-drop interface – Uploading and highlighting is effortless.
✔ Multi-purpose platform – Includes editing, compressing, and converting PDFs.
✔ Cloud integration – Easily upload from and save to Google Drive or Dropbox.
Limitations:
✘ Free version has daily usage limits.
✘ Some features require a premium subscription.
3. Sejda PDF Editor – Direct Text Selection & Highlighting
If you’re looking for a tool that allows you to highlight text directly without converting files, Sejda PDF Editor is a strong choice.
✔ Works on both text-based and scanned PDFs (with OCR).
✔ Allows color customization – Choose different highlight shades for better organization.
✔ No sign-up required for basic use.
Limitations:
✘ Free usage is limited to three tasks per hour.
✘ Larger PDFs may require a paid upgrade.
4. DocHub – Ideal for Google Drive Users
For those who frequently work with Google Drive, DocHub is a convenient option.
✔ Seamless Google Drive and Dropbox integration – Open and save files directly.
✔ Auto-save feature – Ensures you never lose progress.
✔ Additional annotation tools – Add comments, underline text, and sign documents.
Limitations:
✘ Requires a Google login for full functionality.
✘ Some features (like unlimited storage) require a premium upgrade.
Which One Should You Choose?
- For a quick and free highlight option → PDF4Sure.
- If you want an all-in-one PDF toolkit → Smallpdf.
- For advanced highlighting with color options → Sejda PDF Editor.
- If you frequently use Google Drive → DocHub is best.
Each of these tools makes highlighting PDFs online simple and hassle-free. Choose the one that fits your workflow best!
How to Highlight in a Scanned PDF
Ever tried to highlight text in a scanned PDF, only to realize that it doesn’t work? That’s because scanned PDFs are essentially images, not editable text. But don’t worry! With the right tools, you can convert these PDFs into highlightable, searchable documents. Here’s how.
Why Scanned PDFs Don’t Allow Direct Highlighting
Unlike regular PDFs, where the text is selectable, scanned PDFs are just images of text. This means:
- You can’t copy, search, or highlight the text directly.
- A PDF reader sees the file as a picture, not an editable document.
- To highlight, you first need to convert the scanned text into a digital format using OCR (Optical Character Recognition).
Using OCR to Convert Scanned PDFs
OCR tools scan your PDF, recognize the text within images, and convert it into an editable format. Here’s how to use OCR to enable highlighting:
1. Upload your scanned PDF to an OCR tool.
2. Run the OCR process – The tool extracts text from the image.
3. Download the converted PDF – Now, the text is selectable and highlightable.
4. Open in any PDF highlighter (like Smallpdf, Sejda, or Adobe Acrobat) and highlight as needed.
Best Free Online OCR Tools
✔ Adobe Scan (Best for mobile users)
- Converts scanned PDFs into highlightable text.
- Works seamlessly with Adobe Acrobat Reader.
- Available as a free mobile app for scanning documents.
✔ Smallpdf OCR (Best for quick online conversion)
- Simple drag-and-drop interface.
- Converts scanned PDFs into editable text for highlighting.
- Free version has limits on daily conversions.
✔ OnlineOCR.net (Best for occasional use)
- Free and doesn’t require registration.
- Supports multiple languages for text recognition.
- Works well for single-page PDFs but has limits for multi-page files.
Final Steps: Highlighting After OCR Conversion
Once you’ve converted your scanned PDF into an editable format, you can:
1. Open it in any PDF editor (Smallpdf, Sejda, PDF4Sure).
2. Use the highlighter tool to mark important text.
3. Save and download your newly highlighted PDF.
Pro Tips for Efficient PDF Highlighting
Highlighting a PDF isn’t just about marking text—it’s about organizing information effectively. Whether you’re studying, reviewing documents, or proofreading, these expert tips will help you highlight smarter and stay organized.
1. Use Color Coding for Better Organization
Instead of using just one color, assign different highlight colors for different purposes. This makes it easier to scan through a document later.
✔ Yellow – General highlights, important points.
✔ Blue – References, citations, or external sources.
✔ Red – Errors, corrections, or things to revisit.
✔ Green – Actionable items or key takeaways.
Most online PDF highlighters (like Sejda and Smallpdf) allow you to choose highlight colors, so take advantage of this feature!
2. Organize Highlights by Adding Comments or Notes
Highlighting without context can be confusing later. Adding short notes next to your highlights can make your annotations more meaningful.
✔ Summarize key points – Add a quick explanation of why you highlighted a section.
✔ Use sticky notes – Many PDF editors, including Adobe Acrobat and DocHub, let you insert comments.
✔ Create a key – If you’re using multiple colors, include a note at the start of your document explaining what each color means.
3. Store and Access Highlighted PDFs Anywhere
Keeping your highlighted PDFs in cloud storage ensures you can access them anytime, anywhere.
✔ Google Drive – Syncs across devices and allows easy sharing.
✔ Dropbox – Works well for organizing large PDF files.
✔ OneDrive – Great for Microsoft users with seamless integration.
Highlighting everything defeats the purpose. Instead, be selective—focus on key ideas and critical information. A well-structured highlight strategy can turn any PDF into a powerful study or reference tool.
Conclusion: Highlight Smarter, Not Harder
Highlighting PDFs doesn’t have to be a hassle. With the right tools and strategies, you can easily mark up important information, stay organized, and improve your workflow, whether you’re studying, reviewing reports, or editing documents.
If you’re working with a scanned PDF, use OCR tools like Adobe Scan or Smallpdf to convert it into selectable text. This makes highlighting possible even in image-based PDFs. For standard PDFs, choose an online highlighter that fits your needs—Sejda for color customization, PDF4Sure for quick edits, or DocHub for seamless Google Drive integration.
To stay organized, apply color coding: yellow for key points, blue for references, and red for corrections. Adding comments or notes to your highlights can also make them more meaningful. Finally, storing your PDFs in cloud storage like Google Drive or Dropbox ensures you can access your highlighted files from anywhere.
By using these simple yet effective techniques, you’ll never lose track of important details again. Whether you’re a student, researcher, or professional, smart PDF highlighting will make your documents clearer, more useful, and easier to review!
FAQs: Solving Common Highlighting Issues
1. Why Can’t I Highlight Text in My PDF?
If your PDF won’t let you highlight text, it’s likely because:
✔ The file is scanned (not selectable text). Use an OCR tool like Smallpdf or Adobe Scan to convert it.
✔ The PDF is locked or restricted (editing permissions are disabled).
2. How Do I Highlight in a Locked PDF?
If a PDF is password-protected or has restricted editing:
✔ Check permissions – If you have the password, unlock it using Adobe Acrobat or ILovePDF.
✔ Use an online unlock tool – Some sites (like Smallpdf) can remove restrictions if allowed.
3. Can I Change the Highlight Color?
Yes! Most PDF editors, like Sejda and PDF4Sure, allow you to:
✔ Choose from different highlight colors.
✔ Adjust opacity and thickness for better visibility.
4. What’s the Best Free PDF Highlighter?
It depends on your needs:
✔ For quick online highlighting → PDF4Sure.
✔ For color customization → Sejda PDF Editor.
✔ For Google Drive users → DocHub.
5. Can I Remove Highlights from a PDF?
Yes! Most PDF editors allow highlight removal. Simply:
✔ Click on the highlighted text and press Delete.
✔ Use an eraser tool in apps like Adobe Acrobat or Smallpdf.