Underline PDF Like a Pro: Your Ultimate Guide for Windows, Mac, iOS, and Android

Welcome to our comprehensive step-by-step guide on how to underline in PDF documents. Whether you need to emphasize key points, highlight essential information, or add clarity to your PDFs, underlining text can be a powerful tool. In this guide, we'll walk you through the process of underlining text in PDF.

How to Underline in PDF on Windows and Mac?

Introducing UPDF, a feature-rich PDF editor and annotator for Windows and Mac. With it, you can effortlessly annotate PDFs, edit text and images, organize and convert PDF pages, utilize OCR, and access files through UPDF Cloud. Whether you're on Windows or Mac, UPDF provides a seamless solution for all your PDF editing needs, including the ability to underline important text in just a few simple steps.

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Supports macOS 10.14.6 or later100% secure

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To underline text in a PDF on both Windows and Mac using UPDF, follow these steps:

  • Open the PDF document you wish to underline text in.
  • Locate the "Comment" icon on the left toolbar and click on it.
  • From the markup options on the top toolbar, select the underline symbol to enable the underline feature.
  • Once the underline feature is activated, hover your cursor over the text you want to underline.
  • To customize the underline color, double-click on the underline option and choose the desired color from the available options.
underline pdf

How to Underline Text in a Scanned PDF on Windows and Mac?

To underline text in a scanned or image-based PDF, you can use UPDF's OCR feature, these are the simple steps you need to follow!

  • Open your scanned PDF in UPDF and hit "Recognize Text Using OCR". 
  • In the popping-up menu, select the layout, set your language from one of the 38 supported ones, and select the page range if you need it.
  • Hit "Perform OCR" to convert your scanned PDF into the edited one. 
  • Once done with the conversion, follow the same steps as in the above guide to highlight text in your recently converted PDF. 
underline scanned pdf

How to Underline in PDF on iPhone and iPad?

In this guide, we will explore how to underline text in PDFs on iOS devices using UPDF for iOS; here are the steps to do it:

  • Open the UPDF application on your device.
  • Open the PDF document you wish to annotate.
  • You'll see a pencil icon, tap on it, and it'll reveal all the annotation tools.
  • Tap on "Markup" and select the underline option.
underline text in pdf on ios
  • Now all the markup tools will be revealed. You can choose the underline icon at the bottom.
  • Hover your finger over the text you want to underline and save your changes.
underline pdf on iphone and ipad

How to Underline in PDF on Android?

With UPDF for Android, you can easily emphasize key information and enhance the readability of your PDFs. Follow the instructions below to learn how to underline text in PDF on Android using UPDF:

  • Launch the UPDF app on your Android device.
  • Open the PDF document you want to underline.
  • Tap on the "Pen" icon and then the "Markup" icon located at the top of the interface.
  • Select the underline option from the available markup tools.
  • Hover your finger over the text you wish to underline to highlight it.
  • For further customization, long-press the underline option to choose a different color or thickness.
underline pdf on android

Benefits of Underling Text in PDF

Underlining text in PDF documents offers numerous benefits that enhance readability, emphasize key information, and improve overall document comprehension. Whether you're a student, professional, or avid reader, underlining text in PDFs can greatly enhance your reading and studying experience. Let's explore the benefits in more detail:

Emphasize Important Information

You can highlight and draw attention by underlining crucial points, key concepts, or essential details within the document. By visually emphasizing specific text, you can quickly and easily identify and remember important information.

Enhance Readability

Another benefit of underlining text is that it improves the readability of PDF documents, making it easier to skim through and navigate the content. The underlined sections stand out from the rest of the text, providing visual cues and guiding the reader's attention.

Study and Research Aid

By underlining your text in a PDF document, you can keep your PDF organized and categorize information, making it easier to review and revisit important points. By underlining in PDFs, you can create concise summaries, extract key ideas, and effectively annotate your study materials.

Document Annotation

Underlining serves as a form of annotation, allowing you to mark up PDFs and add your insights or thoughts directly onto the document. This makes it convenient for personal note-taking, collaborative work, or sharing feedback on drafts and reports.

Efficient Document Review

When reviewing lengthy PDF documents, underlining important text enables quick referencing and efficient information retrieval. It saves time by allowing you to locate and review key sections without reading the entire document.

Visual Organization

By underlining text, you can visually organize information within a PDF. This is especially helpful for categorizing ideas, creating hierarchies, or distinguishing between different types of content. It provides a clear structure and improves the overall visual appeal of the document.

Improved Document Navigation

When revisiting PDFs at a later time, underlining helps you navigate through the document more effectively. By underlining significant sections, you can easily skim and find the specific information you need without having to go through the entire document again.

Compatibility and Portability

Underlining in PDFs ensures that the annotations and underlined text remain intact when sharing or transferring the document across different devices or platforms. This makes it easy to access and review your underlined PDFs on various devices and with different PDF readers, including UPDF.


FAQs on Underline in UPDF

Here are some FAQs regarding underlining PDFs:

Why Can't I Underline a PDF?

There are several reasons why you may be unable to underline text in a PDF. One common reason is that your PDF might be scanned, meaning it is essentially an image file rather than a text-based document. To overcome this limitation, you would need to utilize OCR (Optical Character Recognition) technology. OCR allows you to convert scanned PDFs into editable and searchable text.

By running the scanned PDF through an OCR software or tool, it analyzes the image and recognizes the characters, converting them into editable text. Once the PDF has undergone OCR and the text has been recognized, you can then proceed to underline the desired text within the document. OCR technology enables you to unlock the full editing potential of scanned PDFs, including the ability to underline, highlight, or modify the text as needed.

Which App is Used to Underline PDF?

UPDF is an excellent app that can be used to underline text in PDF documents. It provides a user-friendly interface and comprehensive annotation features, making it an ideal choice for enhancing your PDF reading and editing experience. With UPDF, you can easily select the text you want to underline and apply the underline formatting with just a few taps or clicks.

The app also offers additional customization options, allowing you to choose different colors or thicknesses for the underline. Whether you're using it on Windows, Mac, iOS, or Android, you can enjoy the convenience and versatility of underlining text in your PDFs. Its intuitive interface and powerful features make it a top choice for individuals who need to annotate and underline text in their PDF documents.

How Do I Draw a Line in a PDF?

To draw a line in a PDF using UPDF, follow these simple steps:

  1. Launch the UPDF tool and import the PDF file you want to annotate by clicking the "Open File" button.
  2. To access the drawing tools, click on the "Comment" button, which will reveal the annotation options in the UPDF toolbar.
  3. Locate the "Pencil" icon at the top of the toolbar and click on it. This will activate the drawing mode, allowing you to draw freehand lines, and shapes or write text.
  4. With the Pencil tool activated, you can now draw a line in the PDF. Simply click and drag to create the desired line.
  5. You can also utilize pre-designed shapes available in UPDF to add more variety and color to your annotations. Furthermore, UPDF allows you to adjust the colors and opacity of the drawn shapes.

Wrap Up!

Underlining text in PDF documents is a valuable feature that enhances readability and emphasizes important information. With UPDF, you can easily underline text in PDFs using the intuitive interface and powerful annotation tools.

By following these step-by-step instructions, you can effortlessly underline text in your PDFs, making them more engaging and impactful. Also, UPDF has a 54% sale on its pricing, so seize the opportunity and purchase it now!

Supports Windows 7 or later100% secure

Supports macOS 10.14.6 or later100% secure

100% secure

100% secure