diff --git a/QuestPDF/Previewer/UnitTestDetector.cs b/QuestPDF/Previewer/UnitTestDetector.cs
new file mode 100644
index 0000000..c2a02c6
--- /dev/null
+++ b/QuestPDF/Previewer/UnitTestDetector.cs
@@ -0,0 +1,20 @@
+using System;
+using System.Linq;
+
+namespace QuestPDF.Previewer;
+
+internal static class UnitTestDetector
+{
+    public static bool RunningInUnitTest { get; }   
+
+    private static string[] UnitTestAssemblies = { "xunit", "nunit", "mstest" };
+    
+    static UnitTestDetector()
+    {
+        RunningInUnitTest = AppDomain
+            .CurrentDomain
+            .GetAssemblies()
+            .Select(x => x.FullName.ToLowerInvariant())
+            .Any(x => UnitTestAssemblies.Any(x.Contains));
+    }
+}
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