Last updated on
Sep 8, 2026
Go beyond editing and add context to your changes. After fixing a typo or updating a section, drop a comment or highlight the area to pinpoint and explain edits.
Underline in PDF
Learn how to underline text in PDF documents using pdfFiller's intuitive tools for quick and easy annotation.
What is the Underline Tool in PDF?
The underline tool in PDF allows you to highlight text effectively. This tool is particularly useful for document review, enabling you to annotate important sections clearly. It supports scanned PDFs, making it ideal for small businesses that need to mark up documents without complicated processes. With this tool, you can easily identify key information and enhance the overall readability of your documents.
How Does Underlining Improve Document Workflows?
Underlining text in PDF increases readability and helps facilitate collaboration among team members. By marking important points, you can save time on revisions and ensure that everyone is on the same page. This feature works on any device, allowing you to annotate documents whether you are in the office or on the go. The ability to highlight essential information makes it easier for teams to understand and act on feedback quickly.
Step-by-Step Guide to Underlining in PDF
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1.Access pdfFiller in your web browser.
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2.Select the underline tool from the toolbar.
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3.Click and drag your cursor over the text you want to underline.
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4.Review the underlined text to ensure accuracy.
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5.Save your changes to the PDF document.
Managing Annotations After Underlining
To manage your annotations after underlining, select the underlined text to modify it. You can change the color or thickness of the underline to better suit your preferences. If needed, you can also remove the underline option entirely. Remember to save the document after making any changes to ensure your edits are preserved.
Common Scenarios for Underlining in PDFs
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1.Annotating contracts for legal professionals to highlight critical clauses.
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2.Reviewing proposals to emphasize key points for client discussions.
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3.Marking invoices to draw attention to payment terms and due dates.
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4.Collaborating on reports by underlining essential data for team members.
Limitations of the Underline Tool
The underline tool in PDF has some limitations. It cannot underline images, as it is limited to text only. Additionally, there is no batch processing available, meaning you must underline text individually. Some PDFs may not support this feature, particularly if they are not text-based, which can restrict your editing capabilities.
Collaborating with Underlined PDFs
Underlined PDFs enhance teamwork by allowing you to share documents easily with colleagues. You can collect feedback directly on the document, track changes made by others, and use the annotations on any device. This collaborative approach ensures that everyone involved can contribute effectively without complicated sharing methods.
Next Steps for Effective Document Annotation
To further improve your document management, explore other annotation tools available in pdfFiller. You can integrate with e-signatures for a complete workflow, utilize templates for consistent formatting, and access your documents on mobile devices. These PDF features will enhance your overall productivity and make document handling more efficient.
How Does pdfFiller Compare?
Adobe Acrobat offers comprehensive PDF editing features but comes with a steeper learning curve and higher costs.
Smallpdf provides basic PDF editing tools but lacks the extensive template library and collaborative features of pdfFiller.
PDF Expert is known for its user-friendly interface, but it doesn't offer the same level of integration with e-signature workflows as pdfFiller.
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Online PDF annotation: Highlight, redact, draw, and comment
Annotate and edit
Guide every signature
Use annotation tools to highlight important sections, redact sensitive details, or add comments to clarify contract clauses before you send the document for signing.
Team feedback, simplified
Stop juggling feedback across endless email chains. Share your document and let everyone add their highlights, comments, and suggestions directly on the PDF.
All your notes in one place
Never lose track of important feedback. All annotations are saved with your documents in your secure cloud storage, keeping your projects organized and accessible.
How to annotate a PDF?
1. Upload
Upload your document to pdfFiller and open it in the editor.
2. Annotate
Use annotation tools at the top to highlight, redact, draw, add markings, and leave comments.
3. Save and export
Apply your changes and choose how to export your document: download, send to cloud storage, save in your account, share, and more.
Who uses this tool?
Learn how professionals use pdfFiller to review documents and exchange feedback.
Business Owners
Review business plans or financial reports and add notes directly on the document for your team. Highlight key performance indicators and comment on specific sections to provide clear feedback without altering the original file.
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Financial reports
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Business plans
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Marketing mockups
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Strategic roadmaps
Sales
Collaborate on proposals and contracts before they are sent to clients. Highlight key terms for internal review or add notes to a presentation to prepare your team for a big meeting.
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Sales proposals
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Draft contracts
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Presentation slides
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Competitor analysis reports
Real Estate
Simplify communication with clients and partners. Highlight critical clauses in purchase agreements or point out concerns on inspection reports to ensure everyone is on the same page.
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Inspection reports
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Purchase agreements
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Floor plans
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Property disclosure forms
Construction
Streamline project reviews by allowing architects, contractors, and clients to mark up plans. Draw arrows to indicate changes on blueprints, comment on change orders, or flag issues on safety reports to keep projects on track.
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Blueprints and architectural plans
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Project bids
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Change orders
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Safety reports
Healthcare
Collaborate with colleagues to enhance patient care or medical research. Highlight key findings in lab reports or add notes to a medical research paper without compromising the original document’s integrity.
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Patient charts
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Lab results
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Peer review documents
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Medical research papers
Insurance
Expedite claims and underwriting by quickly annotating case documents. A claims adjuster can circle damage on a photo, and an underwriter can highlight missing information on an application, ensuring an efficient review process.
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Claim forms with photos
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Witness statements
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Policy applications
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Investigation reports
Legal
Speed up document reviews with confidential notes and highlights. Mark up discovery documents with key evidence, comment on witness depositions, or add case analysis notes for your team while preserving the original file.
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Discovery documents
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Witness depositions
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Affidavits
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Case law research
Why trust pdfFiller to annotate your documents?
All-in-one solution
Handle all your document tasks in one place. Create and edit PDFs, collect data and signatures, collaborate, and manage files securely in the cloud.
Cloud-native accessibility
pdfFiller is entirely cloud-based and cross-platform, allowing you to access your documents anytime and anywhere, without installing any software or storing files on multiple devices.
Your documents—secured
pdfFiller prioritizes data protection and regulatory compliance through security measures like data encryption and signer authentication.
pdfFiller scores top ratings on review platforms
I love this app. It allows me to professionally alter projects and makes the job that much easier.
New to this application , let me try it .
Although Adobe Acrobat is what I'm use to this is a program that works well and is affordable.
Not so user friendly. It took me a while to figure out how to make adjustments to the form. It okay now.
Good for beginners, user-friendly, and ability to download
This is super easy and when I needed…
This is super easy and when I needed something, I went on chat and voila, he told me exactly how to split a file and done!!!
Watch our PDF editor in action
Check out this video tutorial to learn how to edit and annotate PDFs using pdfFiller’s drag-and-drop editor.
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How can I easily underline text in a PDF document using pdfFiller?
To underline text in a PDF document using pdfFiller, simply open your PDF in the editor, select the 'Highlight' tool, and choose the underline option. This allows you to draw a line beneath the selected text, making it stand out. For best results, ensure you adjust the line thickness and color to match your document's style. This feature is particularly useful for remote professionals and legal teams who need to emphasize important information in contracts or reports.
Is it possible to underline text in a scanned PDF file with pdfFiller?
Yes, you can underline text in a scanned PDF file using pdfFiller's OCR (Optical Character Recognition) technology. First, upload your scanned PDF, and the OCR feature will convert the image text into editable text. Once converted, use the underline tool to highlight key points. This is especially beneficial for SMEs needing to digitize and annotate physical documents securely and efficiently.
What are the security protocols in place when underlining in PDF documents on pdfFiller?
pdfFiller employs robust security protocols, including encryption and secure cloud storage, ensuring that your documents remain confidential while you underline in PDF files. When you use the underline feature, your data is protected from unauthorized access. This is crucial for legal teams and remote professionals who handle sensitive information and require a secure document management solution.
Can I underline text in a PDF on multiple devices using pdfFiller?
Absolutely! pdfFiller allows you to underline text in a PDF on multiple devices, thanks to its cloud-based platform. You can start editing on your desktop and continue on your tablet or smartphone without losing any changes. This cross-platform compatibility is ideal for remote professionals who need to manage documents on the go, ensuring that you can underline important text wherever you are.
What are the benefits of underlining text in a PDF for document collaboration?
Underlining text in a PDF enhances document collaboration by clearly marking important sections for review. When team members underline key points, it facilitates focused discussions and feedback. Using pdfFiller’s collaborative tools, you can share your underlined documents securely, making it easier for legal teams and SMEs to streamline their workflows and improve communication.
How can I remove or edit underlined text in a PDF using pdfFiller?
To remove or edit underlined text in a PDF using pdfFiller, select the underline tool again, and click on the underlined text you wish to modify. You can change the color, thickness, or completely remove the underline. This flexibility is essential for remote professionals who need to make adjustments quickly and efficiently, ensuring that their documents remain accurate and professional.
Are there any tips for effectively using the underline feature in PDF documents?
When using the underline feature in PDF documents, consider the context of the text you are emphasizing. Use contrasting colors to ensure visibility and avoid over-using the underline tool, as it can clutter the document. Additionally, combine underlining with other annotation tools like comments or highlights for a comprehensive review process. This approach is particularly useful for legal teams and SMEs looking to enhance document clarity and collaboration.
