BrotliSharpLib 0.3.1

There is a newer version of this package available.
See the version list below for details.
dotnet add package BrotliSharpLib --version 0.3.1
NuGet\Install-Package BrotliSharpLib -Version 0.3.1
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="BrotliSharpLib" Version="0.3.1" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add BrotliSharpLib --version 0.3.1
#r "nuget: BrotliSharpLib, 0.3.1"
#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 BrotliSharpLib as a Cake Addin
#addin nuget:?package=BrotliSharpLib&version=0.3.1

// Install BrotliSharpLib as a Cake Tool
#tool nuget:?package=BrotliSharpLib&version=0.3.1


BrotliSharpLib is a full C# port of the brotli library/compression code by Google. It is intended to be a mostly 1:1 conversion of the original C code. All code is correct as of v0.6.0 of the reference implementation.

The projects uses a minimal set of APIs to ensure compatibility with a wide range of frameworks including .NET Standard and .NET Core. It also supports little-endian and big-endian architectures and is optimised for x86, x64 and ARM processors.

BrotliSharpLib is licensed under MIT.


BrotliSharpLib can be installed via the NuGet package here.

Install-Package BrotliSharpLib


Generic/basic usage:

/** Decompression **/
byte[] brotliCompressedData = ...; // arbritary data source
byte[] uncompressedData = Brotli.DecompressBuffer(brotliCompressedData, 0, brotliCompressedData.Length /**, customDictionary **/);

/** Compression **/
byte[] uncompressedData = ...; // arbritary data source

// By default, brotli uses a quality value of 11 and window size of 22 if the parameters are omitted.
byte[] compressedData = Brotli.CompressBuffer(uncompressedData, 0, uncompressedData.Length /**, quality, windowSize, customDictionary **/);

Stream usage:

/** Decompression **/
using (var ms = new MemoryStream())
using (var bs = new BrotliStream(compressedStream, CompressionMode.Decompress))

/** Compression **/
using (var fs = File.OpenRead(filePath))
using (var ms = new MemoryStream())
    using (var bs = new BrotliStream(ms, CompressionMode.Compress))
        // By default, BrotliSharpLib uses a quality value of 1 and window size of 22 if the methods are not called.
        /** bs.SetQuality(quality); **/
        /** bs.SetWindow(windowSize); **/
        /** bs.SetCustomDictionary(customDict); **/
        /* IMPORTANT: Only use the destination stream after closing/disposing the BrotliStream
           as the BrotliStream must be closed in order to signal that no more blocks are being written
           for the final block to be flushed out 
        byte[] compressed = ms.ToArray();

Real-life example: The following allows for acceptance and decompression of brotli encoded web content via a HttpClient and falls back to gzip or deflate when required.

static class HttpClientEx
    private class BrotliCompressionHandler : DelegatingHandler
        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
            request.Headers.AcceptEncoding.Add(new StringWithQualityHeaderValue("br"));
            var response = await base.SendAsync(request, cancellationToken);
            IEnumerable<string> ce;
            if (response.Content.Headers.TryGetValues("Content-Encoding", out ce) && ce.First() == "br")
                var buffer = await response.Content.ReadAsByteArrayAsync();
                response.Content = new ByteArrayContent(Brotli.DecompressBuffer(buffer, 0, buffer.Length));
            return response;

    public static HttpClient Create()
        var handler = new HttpClientHandler();
        if (handler.SupportsAutomaticDecompression)
            handler.AutomaticDecompression = System.Net.DecompressionMethods.Deflate | System.Net.DecompressionMethods.GZip;
        return HttpClientFactory.Create(handler, new BrotliCompressionHandler());


Considerations for Build

For optimal performance, ensure to build BrotliSharpLib in Release mode to enable all possible JIT optimisations.

Performance can also be further improved by building BrotliSharpLib using .NET Framework 4.5 or above (or any framework that supports AggressiveInlining). Selecting a specific target platform (instead of AnyCPU) where possible can also further improve performance. All of this however, is completely optional as BrotliSharpLib is designed to run in a wide range of contexts and configurations regardless.


The following are benchmark results using DotNetBenchmark with BrotliSharpLib (v0.2.1) and Google's C# implementation built against .NET Framework 4.6.1. The original C version was compiled in Release mode using Visual Studio 2017 (v141) as a 64-bit Windows executable.

BenchmarkDotNet=v0.10.6, OS=Windows 10 Redstone 2 (10.0.15063)
Processor=Intel Core i5-6600K CPU 3.50GHz (Skylake), ProcessorCount=4
Frequency=3421875 Hz, Resolution=292.2374 ns, Timer=TSC
  [Host]       : Clr 4.0.30319.42000, 64bit RyuJIT-v4.7.2046.0
  RyuJitX64    : Clr 4.0.30319.42000, 64bit RyuJIT-v4.7.2046.0

File: UPX v3.91 (Windows Executable)

Method Mean
GoogleImpl 12.75 ms
BrotliSharpLib 11.63 ms
Original C 11.17 ms

As seen above, BrotliSharpLib performs close to the original C version in terms of decompression.


File: plrabn12.txt

Method Quality Mean
BrotliSharpLib 1 9.132 ms
Original C 1 9.570 ms
BrotliSharpLib 6 58.720 ms
Original C 6 36.540 ms
BrotliSharpLib 9 116.318 ms
Original C 9 73.080 ms
BrotliSharpLib 11 1822.702 ms
Original C 11 877.58 ms

While BrotliSharpLib performs comparatively at lower quality levels, it performs up to three times worse at level 11. Future versions of the port will hopefully bring this down.

Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 was computed.  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 netcoreapp1.0 is compatible.  netcoreapp1.1 is compatible.  netcoreapp2.0 was computed.  netcoreapp2.1 was computed.  netcoreapp2.2 was computed.  netcoreapp3.0 was computed.  netcoreapp3.1 was computed. 
.NET Standard netstandard1.3 is compatible.  netstandard1.4 was computed.  netstandard1.5 was computed.  netstandard1.6 is compatible.  netstandard2.0 is compatible.  netstandard2.1 was computed. 
.NET Framework net20 is compatible.  net35 is compatible.  net40 is compatible.  net403 was computed.  net45 is compatible.  net451 is compatible.  net452 is compatible.  net46 was computed.  net461 was computed.  net462 is compatible.  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 tizen30 was computed.  tizen40 was computed.  tizen60 was computed. 
Universal Windows Platform uap was computed.  uap10.0 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 1.0

  • .NETCoreApp 1.1

  • .NETFramework 2.0

    • No dependencies.
  • .NETFramework 3.5

    • No dependencies.
  • .NETFramework 4.0

    • No dependencies.
  • .NETFramework 4.5

    • No dependencies.
  • .NETFramework 4.5.1

    • No dependencies.
  • .NETFramework 4.5.2

    • No dependencies.
  • .NETFramework 4.6.2

    • No dependencies.
  • .NETStandard 1.3

  • .NETStandard 1.6

  • .NETStandard 2.0

    • No dependencies.

NuGet packages (21)

Showing the top 5 NuGet packages that depend on BrotliSharpLib:

Package Downloads

Package Description


Rapid Apache Avro serializer for .NET.


HttpReports is a lightweight APM system developed for .NET Core


Pineapple is a set of core libraries that includes utilities, primitives, helper classes for .NET! The inspiration for Pineapple comes from Google's Guava framework.

WebMarkupMin.AspNet.Brotli The ID prefix of this package has been reserved for one of the owners of this package by

WebMarkupMin.AspNet.Brotli contains one compressor-adapter for compression of text content by using the Brotli algorithm ( - `BrotliCompressor`. `BrotliCompressor` is based on the BrotliSharpLib ( version 0.3.3. In version for .NET Standard 2.1, .NET 6 and .NET 7 uses the built-in compressor from the `System.IO.Compression` namespace. If you are using extensions for ASP.NET Core 3.1 or higher, then you should use a `BuiltInBrotliCompressor` class from `WebMarkupMin.AspNet.Common.Compressors` namespace instead of a `BrotliCompressor` class. In this case, the WebMarkupMin.Brotli package will no longer be needed and you can uninstall it.

GitHub repositories (10)

Showing the top 5 popular GitHub repositories that depend on BrotliSharpLib:

Repository Stars
[.NET] m3u8 downloader 开源的命令行m3u8/HLS/dash下载器,支持普通AES-128-CBC解密,多线程,自定义请求头等. 支持简体中文,繁体中文和英文. English Supported.
录播姬 | mikufans 生放送录制
A cross-platform asynchronous HTTP(S) proxy server in C#.
HttpReports is an APM (application performance monitor) system for .Net Core.
Version Downloads Last updated
0.3.3 3,086,036 2/6/2019
0.3.2 17,365 12/9/2018
0.3.1 118,391 10/5/2018
0.3.0 8,630 7/3/2018
0.2.1 62,731 7/16/2017
0.2.0 1,778 6/28/2017