FileTypeInterrogator 1.0.0

.NET Standard 1.3
There is a newer version of this package available.
See the version list below for details.
dotnet add package FileTypeInterrogator --version 1.0.0
NuGet\Install-Package FileTypeInterrogator -Version 1.0.0
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="FileTypeInterrogator" Version="1.0.0" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add FileTypeInterrogator --version 1.0.0
#r "nuget: FileTypeInterrogator, 1.0.0"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install FileTypeInterrogator as a Cake Addin
#addin nuget:?package=FileTypeInterrogator&version=1.0.0

// Install FileTypeInterrogator as a Cake Tool
#tool nuget:?package=FileTypeInterrogator&version=1.0.0


netstandard library for detecting file types by 'magic numbers', similar to the file command in Linux/Unix. Useful for validating file uploads instead of trusting file extensions.


IFileTypeInterrogator interrogator = new FileTypeInterrogator();

byte[] fileBytes = File.ReadAllBytes("pdfFile.pdf");

FileTypeInfo fileTypeInfo = interrogator.DetectType(fileBytes);

Console.WriteLine("Name = " + fileTypeInfo.Name);
Console.WriteLine("Extension = " + fileTypeInfo.FileType);
Console.WriteLine("Mime Type = " + fileTypeInfo.MimeType);

// The following output would be displayed:
// Name = Portable Document Format File
// Extension = pdf
// Mime Type = application/pdf

Notice that IFileTypeInterrogator was assigned, meaning custom implementations are welcomed. File definitions are provided in the source and will be regularly updated, feel free to submit an issue or pull request to add other signatures. To quickly provide support for a new signature, create an instance of CustomFileTypeInterrogator:

IFileTypeInterrogator interrogator = new CustomFileTypeInterrogator("path_to_custom_definitions_file", Encoding.UTF8);

FileTypeInfo fileTypeInfo = interrogator.DetectType(...);

It is best to create a single instance and manage it's lifetime through an IOC/DI Container.

Product Versions
.NET net5.0 net5.0-windows net6.0 net6.0-android net6.0-ios net6.0-maccatalyst net6.0-macos net6.0-tvos net6.0-windows net7.0 net7.0-android net7.0-ios net7.0-maccatalyst net7.0-macos net7.0-tvos net7.0-windows
.NET Core netcoreapp1.0 netcoreapp1.1 netcoreapp2.0 netcoreapp2.1 netcoreapp2.2 netcoreapp3.0 netcoreapp3.1
.NET Standard netstandard1.3 netstandard1.4 netstandard1.5 netstandard1.6 netstandard2.0 netstandard2.1
.NET Framework net46 net461 net462 net463 net47 net471 net472 net48 net481
MonoAndroid monoandroid
MonoMac monomac
MonoTouch monotouch
Tizen tizen30 tizen40 tizen60
Universal Windows Platform uap uap10.0
Xamarin.iOS xamarinios
Xamarin.Mac xamarinmac
Xamarin.TVOS xamarintvos
Xamarin.WatchOS xamarinwatchos
Compatible target framework(s)
Additional computed target framework(s)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

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Version Downloads Last updated
1.1.0 23,515 1/31/2022
1.0.0 38,972 7/8/2019

Update to use flat file definitions, unit tested