Top tools for highlighting and annotating PDFs in 2026

If you are looking for the best PDF highlighting tool, pay attention to variants with more extended functionality. The solution can not only help you mark key points, but also add comments and review a PDF document without changing the original meaning of the file content. For users who also need editing, eSigning, form filling, cloud storage, and collaboration, pdfFiller is a strong option because it combines PDF highlighting with a broader online document workflow.

TL;DR

• pdfFiller may function as a PDF highlighting tool for users who need to highlight text, annotate PDFs, add comments, edit documents, request signatures, and manage files online.
• Adobe Acrobat is a familiar choice for professionals who need advanced PDF editing tools, including commenting, markup, security, and scanned document workflows.
• Smallpdf, Microsoft Edge, and PDFgear are convenient options for basic PDF highlighting, especially for free users or quick browser-based markup.
• PDF Expert and Drawboard PDF are useful for focused reading, markup, iPad workflows, Apple Pencil use, and annotation-heavy reviews.
• The right PDF annotator depends on whether you need simple highlights, team feedback, OCR for scanned PDFs, cloud access, or a full PDF editor.

Key takeaways

• PDF highlighting is most useful when readers need to mark specific sections, leave comments, track feedback, or extract notes from long documents.
• A good PDF editor should support more than one highlight color, text boxes, comments, notes, underline tools, drawing tools, and easy removal of highlights.
• OCR is important when working with scanned PDFs because scanned text may not be selectable until the file is converted into searchable text.
• Cloud-based PDF tools can simplify review workflows by keeping files, annotations, and document versions accessible from a browser.
• pdfFiller is best suited for users who want highlighting, PDF editing, forms, eSignatures, and sharing in one account rather than a standalone PDF reader with highlighting functions.

Why does PDF highlighting matter?

PDF highlighting helps readers separate key points from the rest of a document. It is useful for reviewing contracts, marking report findings, giving feedback on drafts, studying training materials, and flagging required changes in forms.

In 2026, PDF highlighting tools range from simple free browser options to full-featured PDF editing software. Some tools focus on reading and note-taking. Others support advanced features such as OCR, redaction, password protection, form filling, cloud storage, and team collaboration.

How we selected the best PDF highlighting tools

We evaluated PDF highlighting tools based on how well they support real document review workflows. The main criteria included:

• Highlighting and annotation tools, including comments, text boxes, notes, underline, drawing, and color options
• Ease of getting started for first-time users and repeat document workflows
• Compatibility with PDF files, scanned PDFs, mobile devices, desktop apps, and browser access
• Collaboration features such as sharing, comments, cloud storage, and cross-device sync
• Advanced features such as OCR, form filling, eSigning, redaction, password protection, and file conversion
• Pricing structure, including free access, free trials, and paid plans where available
• Best-fit use cases for professionals, students, legal teams, medical offices, educators, and business users

To help you make the best choice, it’s worth noting that a comprehensive PDF editor might be the better option. It lets you annotate, edit, sign, convert, and manage documents all in one place. For a detailed comparison of editing features, check out our blog post on the best PDF editors.

1. pdfFiller: Best for highlighting, editing, signing, and managing PDFs online

pdfFiller is a browser-based PDF editor for users who need more than a simple PDF reader. It lets users highlight PDFs, add comments, insert text boxes, edit PDF text, fill forms, request signatures, convert files, and effectively collaborate on PDF documents online.

On its homepage, pdfFiller presents an all-in-one platform for PDF editing and eSignature, where users can upload, modify, sign, and collaborate on documents online.

This makes pdfFiller a convenient option for people who review PDF documents as part of a workflow. Instead of highlighting a PDF in one app, editing it in another, and sending it for signature in a third tool, users can keep those steps in one workspace.

Key features

pdfFiller supports PDF highlighting and annotation along with broader PDF editing. Users can edit text, organize PDF pages, merge files, split documents, convert file formats, create fillable forms, and send documents for eSignature. This is useful when a highlighted document needs to move from review to completion.

pdfFiller also works with multiple file formats, including PDF and DOCX, which helps users who receive documents in different formats and need to prepare them for review, editing, or signing.

Best for

pdfFiller is a strong fit for:

• Business users who review, edit, and send PDF documents often
• Legal teams that need to add comments, highlight clauses, and prepare documents for signature
• HR teams that review forms, policies, onboarding packets, and employee files
• Medical and administrative teams that need to manage forms carefully
• Students and professionals who want online access to highlighted PDFs, notes, and completed documents

It is also useful for users who want access from a browser rather than a desktop-only setup. Cloud storage and online access help users continue working from different devices.

Pricing and plans

Pricing and included features may change, so users should check the current pdfFiller pricing page before choosing a plan.

Pros

• Combines highlighting, annotation tools, editing, form filling, and eSigning
• Works online without requiring a desktop-only workflow
• Supports comments, notes, text boxes, and other markup tools
• Helps users move from review to completion in one document workflow
• Useful for teams that need PDF editing, signing, and cloud document management

Possible limitations

For PDF highlighting alone, a simpler tool may be enough. For users who also need editing, form filling, document management, eSigning, and sharing, pdfFiller offers broader value than a basic highlighting app.

Where pdfFiller stands out

For professionals who handle approvals or signed documents, the broader workflow matters. Highlighting helps during review, while eSignature and form tools help complete the document. See our guide on electronic signatures for more context on signature workflows.

For scanned documents, users should also consider whether they need OCR before highlighting selected text. Learn more in the blog post: How to edit a scanned PDF with OCR.

pdfFiller’s Wikipedia page gives you a more comprehensive view of the product and the functionality; feel free to check it out.

2. Adobe Acrobat: Best for professional PDF editing and advanced review workflows

As a leading name in PDF editing, Adobe Acrobat sets the industry standard. It’s the go-to choice for professionals requiring comprehensive features like detailed editing, commenting, markup, document protection, OCR, redaction, and file conversion.

Adobe Acrobat combines PDF editing, document sharing, eSignature capabilities, and AI-powered document assistance within a single platform for managing and reviewing digital documents.

For PDF highlighting, Acrobat offers familiar annotation tools such as highlight, comments, sticky notes, underline, and drawing markup. Users who already work in Adobe tools may find Acrobat a natural choice.

Key features

Adobe Acrobat is a strong option for users who need precision tools, advanced features, and compatibility with professional PDF workflows. It can be especially useful for legal, finance, design, and enterprise teams that already use Adobe products.

Best for

Adobe Acrobat is best for:

• Professional users who need advanced PDF editing tools
• Teams that require redaction, OCR, document comparison, or security features
• Users who work with complex PDF files and need a mature desktop application
• Organizations that already rely on Adobe software

For legal workflows, Acrobat may be part of a larger document review process. For more context, see Best PDF editors for legal professionals.

pdfFiller or Adobe Acrobat for highlighting documents?

Adobe Acrobat may be stronger for advanced desktop editing, redaction, and technical PDF control. pdfFiller may be more convenient for users who want online PDF editing, highlighting, form filling, signature requests, and document management in one browser-based workflow.

3. Smallpdf: Best for quick browser-based PDF annotation

Smallpdf is a convenient option for users who want to annotate PDFs directly in a browser. It can be useful when a user needs to upload a file, highlight key points, add text, and download the revised PDF without a complicated setup.

To begin editing, simply drag your PDF into the upload area or click “Choose File” to select a document from your device.

Smallpdf is often a good fit for lightweight tasks. Users who do not need a full PDF editor can use it for quick markup and basic document changes.

Key features

Smallpdf supports online PDF tools for editing, conversion, compression, and annotation. Its PDF annotation workflow is designed for browser use, which means users do not need to install a desktop app for simple markup tasks.

Depending on the tool and plan, users may be able to add highlights, text, shapes, drawings, and comments. It is useful for short reviews, simple feedback, and quick edits.

Best for

Smallpdf is best for:

• Free users who need occasional PDF annotation
• Users who want a fast browser option
• Simple document review tasks
• PDF files that do not require complex editing or team workflows

pdfFiller of Smallpdf for highlighting documents?

Smallpdf is a convenient option for quick annotation. pdfFiller is better suited for users who need to keep working after the highlighting step, such as editing content, creating forms, collecting signatures, and managing documents in cloud storage.

4. PDF Expert: Best for Apple users and focused reading workflows

PDF Expert is a PDF reader and editor known for Mac, iPad, and iPhone workflows. It is especially useful for users who review long documents, take notes, and annotate PDFs on Apple devices.

For readers who prefer touch, trackpad, or Apple Pencil workflows, PDF Expert can feel natural. It is often used by students, researchers, consultants, and professionals who spend time reading and marking up documents.

PDF Expert is a PDF editor for macOS and iOS that enables users to edit, annotate, sign, organize, and manage PDF documents on Mac, iPhone, and iPad.

Key features

PDF Expert supports highlighting, notes, comments, drawing, text markup, form filling, and PDF editing. On iPad, it can be useful for reading with a stylus and marking specific sections during review.

Users can highlight text, add notes, underline important terms, and organize annotations while reading. The app is strongest when PDF review happens inside the Apple ecosystem.

Best for

PDF Expert is best for:

• Mac, iPad, and iPhone users
• Students and researchers who read long PDFs
• Professionals who annotate PDF documents with Apple Pencil
• Users who prefer a polished reading and markup experience

pdfFiller or PDF Expert for highlighting documents?

PDF Expert is strong for focused reading and annotation on Apple devices. pdfFiller is stronger for users who need online document workflows across editing, forms, eSignature, collaboration, and file management.

5. Drawboard PDF: Best for annotation-heavy review and real-time markup

Drawboard PDF is designed for PDF markup, review, and collaboration. It is a useful option for users who work with drawings, plans, reports, and documents that require detailed visual feedback.

Drawboard is often used in industries where markups need to be precise and visible. Architecture, engineering, construction, design, and education teams may find its annotation focus useful.

Drawboard PDF is a document review and PDF markup platform that helps teams annotate files, collaborate in real time.

Key features

Drawboard PDF supports highlighting, drawing, comments, shapes, ink tools, and collaborative annotation workflows. Some plans support real-time collaboration, which can help teams review a document together and keep feedback in one place.

The tool is especially useful when markup is more visual than text-based. Users can point to areas, draw shapes, add notes, and review PDF pages with context.

Best for

Drawboard PDF is best for:

• Teams that need visual PDF markup
• Users reviewing plans, reports, drawings, and technical files
• Annotation-heavy workflows
• Real-time document review sessions

pdfFiller or Drawboard PDF for highlighting documents?

Drawboard PDF is strong for detailed markup and visual collaboration. pdfFiller may be a better when the same document also needs editing, forms, signatures, and cloud document management.

6. PDFgear: Best free PDF editor for broad basic functionality

PDFgear is a free PDF editor that supports viewing, editing, converting, filling, signing, and annotating PDF files. It is available on several major platforms, making it a useful option for users who want a no-cost PDF tool.

PDFgear offers free PDF editing, conversion, merging, and eSignature tools across devices.

For highlighting, PDFgear can be a practical choice for users who need basic annotation tools without paying for a subscription. It may also appeal to users who prefer working in a desktop or app environment rather than a browser.

Key features

PDFgear supports PDF reading, editing, annotation, conversion, form filling, and signing. It also includes AI-assisted features in some versions, which may help users summarize documents or work through PDF content faster.

Some users choose PDFgear because it offers many basic PDF tools for free. However, free tools may not always match the workflow depth, collaboration controls, support, or business features of paid PDF software.

Best for

PDFgear is best for:

• Users looking for a free PDF editor
• Students and individuals with basic annotation needs
• Users who want to highlight PDF documents without a paid account
• People who need simple editing, reading, and conversion features

pdfFiller or PDFgear for highlighting documents?

PDFgear is a good option for cost-conscious users who need basic PDF highlighting and editing. pdfFiller is better for users who need cloud storage, business workflows, forms, eSignature requests, and repeat document management.

7. Microsoft Edge: Best free built-in option for simple PDF highlighting

Microsoft Edge includes a built-in PDF reader with basic annotation tools. It is a convenient option for Windows users who need to open a PDF file, highlight text, add notes, and save the document without installing a separate PDF annotator.

Microsoft Edge’s tools for simple PDF operations may fit for personal use.

This makes Edge one of the easiest options for quick PDF highlighting. It is not a full-featured PDF editor, but it works well for simple reading and markup.

Key features

Microsoft Edge can open PDF files in the browser and provide basic markup tools such as highlighting and drawing. Users can save the marked-up file and continue working with it locally or through their preferred cloud storage setup.

Because Edge is already available for many users, it can reduce friction. There is no need to create an account for basic PDF viewing and annotation.

Best for

Microsoft Edge is best for:

• Windows users who need quick PDF highlighting
• Free users with basic markup needs
• Simple reading and review tasks
• Users who do not need editing, OCR, eSigning, or advanced collaboration

pdfFiller or Microsoft Edge for highlighting documents?

Microsoft Edge is a convenient free option for simple PDF highlighting. pdfFiller is a better fit when users need a full PDF editor with annotation tools, editing, forms, sharing, and signature workflows.

Comparison table: Best PDF highlighting tools

How do you choose the right PDF highlighting tool?

Choosing the right PDF highlighting tool depends on your needs. Here’s a quick guide to help you decide:

• Document type: Can you select the text? If not, you might have a scanned document and need a tool with Optical Character Recognition (OCR) to make the text selectable and highlightable.
• Level of feedback: Just highlighting? A basic reader might suffice. But for adding comments, notes, text boxes, or drawings, you’ll need a more robust PDF annotator.
• Workflow: What happens next? For simple highlighting and printing, a free tool or browser extension can work. For more complex workflows involving editing, sharing, e-signing, and cloud storage management, a comprehensive solution like pdfFiller is a better fit.
• Device: Where are you working? Some tools are device-specific (like PDF Expert for Apple products), while browser-based tools like pdfFiller offer flexibility across any device.
• Security: Is the information sensitive? Don’t upload documents with private data to just any tool. Look for features like password protection, access controls, audit trails, and clear data policies to ensure compliance and security.

How to highlight and annotate a PDF in pdfFiller

Here is a simple step-by-step workflow for using pdfFiller as a PDF highlighting tool:

1. Upload your PDF document to pdfFiller.
   

   Use the Add new → Upload document menu in pdfFiller to import files from your device, a direct URL, or a cloud storage of your choice.

2. Open the file in the pdfFiller editor.
3. Select the Highlight tool from the toolbar.
4. Choose a highlight color that fits your review system.
   

   pdfFiller’s Highlight tool allows users to mark important text in PDFs, customize highlight colors, adjust opacity levels, and manage annotations for more effective document review and collaboration.

5. Highlight the selected text or area you want to mark.
   

   pdfFiller’s highlight tool helps users emphasize important text in PDFs while providing quick access to editing, formatting, and annotation management options.

6. Add comments, notes, or text boxes where you need feedback or context.
7. Review the PDF pages to confirm the highlights and annotations are clear.
8. Remove highlights or edit comments if the markup is no longer needed.
9. Save the PDF file to your account by clicking Done.
   

   The Done button in pdfFiller lets users finish editing a PDF and proceed to actions such as saving, downloading, sharing, printing, or requesting electronic signatures.

10. Share, download, print, or send the document for signature if needed.

This workflow is useful when a PDF file needs more than markup. After highlighting, users can edit text, add fillable fields, convert the file, request signatures, or store the completed document for later access.

Practical use cases for PDF highlighting tools

Legal document review

Legal teams can highlight clauses, add comments, flag missing terms, and prepare documents for signature. A full PDF editor is useful when the same file needs markup, edits, and eSignature routing.

HR onboarding

HR teams can highlight required fields, add notes for new hires, and prepare forms for completion. pdfFiller can help when onboarding packets include forms, policies, and signature requests.

Healthcare intake and administration

Healthcare offices may need to mark specific sections of patient intake forms, consent documents, or internal reports. Teams should review privacy and security requirements before choosing any PDF tool for sensitive information.

Education and research

Students and researchers can highlight key points, add notes, and extract ideas from articles, reports, and textbooks. PDF Expert, PDFgear, Edge, and other tools can be helpful depending on the device and workflow.

Business reports and approvals

Managers can highlight metrics, leave comments, and send feedback on reports, proposals, and agreements. Cloud-based tools make it easier to keep annotated files accessible across devices.

Final thoughts

The best PDF highlighting tool is the one that fits the full document workflow, not only the act of adding color to text. Microsoft Edge, Smallpdf, PDFgear, PDF Expert, Drawboard PDF, and Adobe Acrobat all serve different needs, from free basic markup to advanced professional PDF editing.

pdfFiller is a strong choice for users who want to highlight PDFs and comprehensively manage PDFs online in the same platform. It combines annotation tools with PDF editing, forms, file conversion, eSignature workflows, sharing, and cloud document management.

Start a free trial with pdfFiller to highlight, edit, sign, and manage PDF documents online.

Glossary

• PDF highlighting: Marking selected text or areas in a PDF document so that important information is easier to find.
• PDF annotation: Adding comments, notes, highlights, drawings, text boxes, or other markup to a PDF file.
• PDF editor: Software that lets users edit, annotate, convert, organize, protect, or sign PDF documents.
• OCR: Optical character recognition, a process that converts scanned text into selectable and searchable text.
• Scanned PDF: A PDF created from an image scan, often without selectable text until OCR is applied.
• Highlight color: The color used to mark selected text or a highlighted area.
• Text box: A field or annotation that lets users add typed text to a PDF page.
• Cloud storage: Online storage that lets users access files from different devices.
• Cross-device sync: Functionality that keeps files or annotations available across multiple devices.
• Password protection: A security feature that helps restrict access to a PDF document.