PDF Highlighter (Free & Online Tools Tutorial)

Foxit Reader

Foxit Reader is a highly versatile and widely used PDF document reader renowned for its efficient and intuitive features. As a product of Foxit Software, this application has gained popularity for its ability to seamlessly handle PDF documents while offering a plethora of convenient tools for viewing, editing, and annotating files. Whether you're a professional needing to review important documents or an everyday user seeking a user-friendly PDF reader, Foxit Reader stands out as a reliable solution. In this introduction, we will delve into the key features and advantages that make Foxit Reader a preferred choice in the realm of PDF viewing and management.

PDFelement

PDFelement, an exceptional creation by Wondershare, stands at the forefront of PDF editing and management solutions. Renowned for its comprehensive set of features and user-friendly interface, PDFelement empowers individuals and businesses to efficiently handle PDF documents with ease and precision. Whether it's editing, converting, annotating, or securing a PDF document, PDFelement provides a seamless and intuitive experience, making it a go-to tool for professionals and casual users alike. In this introduction, we will explore the capabilities and advantages that make PDFelement a top choice in the realm of PDF software, showcasing its impact on document management and productivity.

IronPDF

Using Foxit Reader and PDFelement PDF editors, you can highlight a PDF file using a graphical interface. But what if you want to highlight text in PDF files using a programming language? IronPDF is a PDF library available in different programming languages like Java, C#, Node.js, and Python that lets you highlight text in code.

IronPDF is a versatile and robust library designed for seamless integration across Java, C#, Node.js, and Python, empowering developers to effortlessly generate, manipulate, and manage PDF documents within their specific programming environments. Whether you're creating web applications, desktop software, or backend services, IronPDF provides a comprehensive set of features to handle diverse PDF requirements. From creating PDFs and modifying content to adjusting properties and interacting with existing PDF documents, IronPDF offers a unified approach, enabling developers to enhance productivity and streamline their PDF-related workflows in all supported programming languages.

using IronPdf;

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();

        // Wrap text in <mark> (or use a CSS background-color) to highlight it
        string html = @"
            <h1>Quarterly Report</h1>
            <p>Revenue grew steadily this year.
               <mark style='background-color:#fff200;'>Net profit rose by 24%</mark>,
               beating every forecast.</p>";

        // Render the HTML to a PDF, preserving the highlight
        PdfDocument pdf = renderer.RenderHtmlAsPdf(html);
        pdf.SaveAs("highlighted.pdf");
    }
}

using IronPdf;

class Program
{
    static void Main()
    {
        var renderer = new ChromePdfRenderer();

        // Wrap text in <mark> (or use a CSS background-color) to highlight it
        string html = @"
            <h1>Quarterly Report</h1>
            <p>Revenue grew steadily this year.
               <mark style='background-color:#fff200;'>Net profit rose by 24%</mark>,
               beating every forecast.</p>";

        // Render the HTML to a PDF, preserving the highlight
        PdfDocument pdf = renderer.RenderHtmlAsPdf(html);
        pdf.SaveAs("highlighted.pdf");
    }
}

Imports IronPdf

Module Program
    Sub Main()
        Dim renderer As New ChromePdfRenderer()

        ' Wrap text in <mark> (or use a CSS background-color) to highlight it
        Dim html As String = "
            <h1>Quarterly Report</h1>
            <p>Revenue grew steadily this year.
               <mark style='background-color:#fff200;'>Net profit rose by 24%</mark>,
               beating every forecast.</p>"

        ' Render the HTML to a PDF, preserving the highlight
        Dim pdf As PdfDocument = renderer.RenderHtmlAsPdf(html)
        pdf.SaveAs("highlighted.pdf")
    End Sub
End Module

using IronPdf;
using IronPdf.Editing;

class Program
{
    static void Main()
    {
        // Load the PDF you want to mark up
        var pdf = PdfDocument.FromFile("report.pdf");

        // A semi-transparent yellow box acts like a highlighter swipe
        string highlight = "<div style='background:#fff200;opacity:0.4;width:240px;height:20px;'></div>";

        // Overlay the highlight, positioned with alignment options
        pdf.ApplyStamp(highlight,
            verticalAlignment: VerticalAlignment.Top,
            horizontalAlignment: HorizontalAlignment.Left);

        pdf.SaveAs("highlighted.pdf");
    }
}

using IronPdf;
using IronPdf.Editing;

class Program
{
    static void Main()
    {
        // Load the PDF you want to mark up
        var pdf = PdfDocument.FromFile("report.pdf");

        // A semi-transparent yellow box acts like a highlighter swipe
        string highlight = "<div style='background:#fff200;opacity:0.4;width:240px;height:20px;'></div>";

        // Overlay the highlight, positioned with alignment options
        pdf.ApplyStamp(highlight,
            verticalAlignment: VerticalAlignment.Top,
            horizontalAlignment: HorizontalAlignment.Left);

        pdf.SaveAs("highlighted.pdf");
    }
}

Imports IronPdf
Imports IronPdf.Editing

Module Program
    Sub Main()
        ' Load the PDF you want to mark up
        Dim pdf = PdfDocument.FromFile("report.pdf")

        ' A semi-transparent yellow box acts like a highlighter swipe
        Dim highlight As String = "<div style='background:#fff200;opacity:0.4;width:240px;height:20px;'></div>"

        ' Overlay the highlight, positioned with alignment options
        pdf.ApplyStamp(highlight, verticalAlignment:=VerticalAlignment.Top, horizontalAlignment:=HorizontalAlignment.Left)

        pdf.SaveAs("highlighted.pdf")
    End Sub
End Module

Conclusion

PDF highlighters are indispensable digital tools revolutionizing the way we interact with PDF documents, providing a versatile and efficient means to mark and emphasize critical information. The ability to simulate traditional highlighter pens in a digital realm not only enhances readability but also facilitates organization and comprehension, making them crucial for students, professionals, and anyone dealing with digital content. This article explored two prominent PDF highlighter options, Foxit Reader and PDFelement, showcasing their intuitive features and highlighting capabilities.

Additionally, we introduced IronPDF, a programming-friendly PDF library, illustrating how it can highlight text in PDFs programmatically—whether at render time or on an existing document—underlining the growing need for seamless integration between PDF tools and programming languages. In a world dominated by digital documentation, PDF highlighters, along with advanced PDF editing solutions, play a pivotal role in enhancing productivity, collaboration, and effective information management across diverse domains.

To learn more about IronPDF and how to edit PDF files, visit the IronPDF Documentation. For more on stamping and styling PDF content with IronPDF, refer to the IronPDF Edit PDF tutorial.