Full Screen Button in PDFViewer

Updated on Dec 10, 2025

Environment

Product	Telerik UI for ASP.NET MVC Upload
Progress Telerik UI for ASP.NET MVC version	Created with the 2023.3.1114 version

Description

How can I add a button that opens the PDF file in full screen when using the PDFViewer component?

Solution

1. Create a custom button in the Toolbar() configuration and specify a toggle event handler.
2. Use the requestFullscreen() and exitFullscreen() methods to toggle the fullscreen mode.

Razor

    <script src="https://cdnjs.cloudflare.com/ajax/libs/pdf.js/2.2.2/pdf.js"></script>
    <script>
        window.pdfjsLib.GlobalWorkerOptions.workerSrc = 'https://cdnjs.cloudflare.com/ajax/libs/pdf.js/2.2.2/pdf.worker.js';
    </script>

    @(Html.Kendo().PDFViewer().Name("pdfviewer")
        .PdfjsProcessing(pdf => pdf
            .File(c => c.Url(Url.Content("~/Document.pdf")))
        )
        .Toolbar(tb => tb.Items(item => item
            .Add()
            .Name("myCustomTool")
            .Icon("fullscreen")
            .Togglable(true)
            .Type("button")
            .Toggle("toggleBtn")
        ))
        .Height(1200)
    )

JS

<script>
    function toggleBtn(ev) {
        var viewerElement = kendo.widgetInstance($("#pdfviewer")).element[0];
        if (getFullscreenElement()) {
            document.exitFullscreen();
        } else {
            viewerElement.requestFullscreen();
        }
    }

    function getFullscreenElement() {
        return document.fullscreenElement
            || document.webkitfullscreenElement
            || document.mozfullscreenElement
            || document.msfullscreenElement
    }
</script>

More ASP.NET MVC PDFViewer Resources

• ASP.NET MVC PDFViewer Documentation

• ASP.NET MVC PDFViewer Demos

• ASP.NET MVC PDFViewer Product Page

• Telerik UI for ASP.NET MVC Video Onboarding Course (Free for trial users and license holders)

• Telerik UI for ASP.NET MVC Forums

See Also

• Client-Side API Reference of the PDFViewer for ASP.NET MVC

• Server-Side API Reference of the PDFViewer for ASP.NET MVC

• Telerik UI for ASP.NET MVC Breaking Changes

• Telerik UI for ASP.NET MVC Knowledge Base