Leopard 2.0.2

dotnet add package Leopard --version 2.0.2                
NuGet\Install-Package Leopard -Version 2.0.2                
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="Leopard" Version="2.0.2" />                
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add Leopard --version 2.0.2                
#r "nuget: Leopard, 2.0.2"                
#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 Leopard as a Cake Addin
#addin nuget:?package=Leopard&version=2.0.2

// Install Leopard as a Cake Tool
#tool nuget:?package=Leopard&version=2.0.2                

Leopard Binding for .NET

Leopard Speech-to-Text Engine

Made in Vancouver, Canada by Picovoice

Leopard is an on-device speech-to-text engine. Leopard is:

  • Private; All voice processing runs locally.
  • Accurate
  • Compact and Computationally-Efficient
  • Cross-Platform:
    • Linux (x86_64), macOS (x86_64, arm64), and Windows (x86_64)
    • Android and iOS
    • Chrome, Safari, Firefox, and Edge
    • Raspberry Pi (5, 4, 3) and NVIDIA Jetson Nano


  • .NET 6.0


Platform compatible with .NET Framework 4.6.1+:

  • Windows (x86_64)

Platforms compatible with .NET Core 2.0+:

  • Linux (x86_64)
  • macOS (x86_64)
  • Windows (x86_64)

Platforms compatible with .NET Core 3.1+:

  • Raspberry Pi:
    • 3 (32 and 64 bit)
    • 4 (32 and 64 bit)
  • NVIDIA Jetson Nano

Platform compatible with .NET 6.0+:

  • macOS (arm64)


You can install the latest version of Leopard by getting the latest Leopard Nuget package in Visual Studio or using the .NET CLI:

dotnet add package Leopard


Leopard requires a valid Picovoice AccessKey at initialization. AccessKey acts as your credentials when using Leopard SDKs. You can get your AccessKey for free. Make sure to keep your AccessKey secret. Signup or Login to Picovoice Console to get your AccessKey.


Create an instance of the engine and transcribe an audio file:

using Pv;

const string accessKey = "${ACCESS_KEY}";
const string audioPath = "${AUDIO_FILE_PATH}";

Leopard leopard = Leopard.Create(accessKey);

LeopardTranscript result = leopard.ProcessFile(audioPath);

Replace ${ACCESS_KEY} with yours obtained from Picovoice Console. Finally, when done release the resources using leopard.Dispose().

Language Model

The Leopard .NET SDK comes preloaded with a default English language model (.pv file). Default models for other supported languages can be found in lib/common.

Create custom language models using the Picovoice Console. Here you can train language models with custom vocabulary and boost words in the existing vocabulary.

Pass in the .pv file via the modelPath argument in the Create() constructor:

const string modelPath = "${MODEL_FILE_PATH}";

Leopard leopard = Leopard.Create(accessKey, modelPath);

Word Metadata

Along with the transcript, Leopard returns metadata for each transcribed word. Available metadata items are:

  • Start Time: Indicates when the word started in the transcribed audio. Value is in seconds.
  • End Time: Indicates when the word ended in the transcribed audio. Value is in seconds.
  • Confidence: Leopard's confidence that the transcribed word is accurate. It is a number within [0, 1].
  • Speaker Tag: If speaker diarization is enabled on initialization, the speaker tag is a non-negative integer identifying unique speakers, with 0 reserved for unknown speakers. If speaker diarization is not enabled, the value will always be -1.


The Leopard dotnet demo project is a .NET Core console app that allows for processing real-time audio (i.e. microphone) and files using Leopard.

Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 is compatible.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 was computed.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed. 
.NET Core netcoreapp2.0 was computed.  netcoreapp2.1 was computed.  netcoreapp2.2 was computed.  netcoreapp3.0 is compatible.  netcoreapp3.1 was computed. 
.NET Standard netstandard2.0 is compatible.  netstandard2.1 was computed. 
.NET Framework net461 was computed.  net462 was computed.  net463 was computed.  net47 was computed.  net471 was computed.  net472 was computed.  net48 was computed.  net481 was computed. 
MonoAndroid monoandroid was computed. 
MonoMac monomac was computed. 
MonoTouch monotouch was computed. 
Tizen tizen40 was computed.  tizen60 was computed. 
Xamarin.iOS xamarinios was computed. 
Xamarin.Mac xamarinmac was computed. 
Xamarin.TVOS xamarintvos was computed. 
Xamarin.WatchOS xamarinwatchos was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.
  • .NETCoreApp 3.0

    • No dependencies.
  • .NETStandard 2.0

    • No dependencies.
  • net6.0

    • No dependencies.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last updated
2.0.2 797 2/5/2024
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