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Fixing Font Kerning Issues in IronPDF

Curtis Chau
Curtis Chau
Updated: July 21, 2026

This issue specifically affects the WebKit version (<= 2021.3.1) of our library. Font kerning issues with system fonts such as Arial and Arial Bold are caused by faulty kerning within the Windows system fonts. To address this issue, we recommend transitioning to a later version of IronPDF. Starting from version (>= 2021.9.3678), we introduced Chrome Engine rendering, which offers improved compatibility and resolves these font kerning issues.

Workaround

To work around the font kerning problem, please remove the system font and download a new font (such as ArialMT) from an online resource. Then, link this font into the HTML using @font-face:

@font-face {
    /* Define a new font family for ArialMT Regular */
    font-family: 'ArialMT Regular'; 
    font-style: normal; 
    font-weight: normal; 
    /* Specify the local source and the WOFF format for the font */
    src: local('ArialMT Regular'), url('arialmt.woff') format('woff'); 
}
Text

Next, replace any font-family: Arial; declaration in your HTML with font-family: ArialMT Regular;, and then render the PDF. This change ensures that the web font is used instead of the potentially problematic system font, thereby avoiding kerning issues caused by the system's default fonts.

Curtis Chau
Technical Writer

Curtis Chau holds a Bachelor’s degree in Computer Science (Carleton University) and specializes in front-end development with expertise in Node.js, TypeScript, JavaScript, and React. Passionate about crafting intuitive and aesthetically pleasing user interfaces, Curtis enjoys working with modern frameworks and creating well-structured, visually appealing manuals.

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C# NuGet Library for PDF
Install with NuGet

Version: 2026.9

PM > Install-Package IronPdf
nuget.org/packages/IronPdf/
  1. In Solution Explorer, right-click References, Manage NuGet Packages
  2. Select Browse and search "IronPdf"
  3. Select the package and install
C# PDF DLL
Download DLL

Version: 2026.9

or download Windows Installer here.

  1. Download and unzip IronPDF to a location such as ~/Libs within your Solution directory
  2. In Visual Studio Solution Explorer, right click References. Select Browse, "IronPdf.dll"

Licenses from $999