Genbox.FastHash 1.0.0-alpha.3

Prefix Reserved
This is a prerelease version of Genbox.FastHash.
dotnet add package Genbox.FastHash --version 1.0.0-alpha.3                
NuGet\Install-Package Genbox.FastHash -Version 1.0.0-alpha.3                
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="Genbox.FastHash" Version="1.0.0-alpha.3" />                
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add Genbox.FastHash --version 1.0.0-alpha.3                
#r "nuget: Genbox.FastHash, 1.0.0-alpha.3"                
#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 Genbox.FastHash as a Cake Addin
#addin nuget:?package=Genbox.FastHash&version=1.0.0-alpha.3&prerelease

// Install Genbox.FastHash as a Cake Tool
#tool nuget:?package=Genbox.FastHash&version=1.0.0-alpha.3&prerelease                

FastHash - High-performance non-cryptographic hashes



  • API supports ReadOnlySpan for optimal performance and flexibility
  • Unsafe API that takes byte* as input. Use this when performance is important.
  • Most of the hashes are verified with test vectors from the original author
  • High-performance zero-allocation implementations
  • Index variants of each hash function that give the same output as if using the hash function, but takes in a 32bit/64bit integer.


These hash functions are included in the library.

Name Version Authors License
CityHash 1.1 Geoff Pike, Jyrki Alakuijala MIT
DJBHash - Daniel J. Bernstein None
FarmHash 1.1 Geoff Pike MIT
FarshHash - Bulat Ziganshin MIT
FNVHash - Glenn Fowler, Landon Curt Noll, Kiem-Phong Vo None
HighwayHash - Jyrki Alakuijala, Bill Cox, Jan Wassenberg Apache 2.0
MarvinHash - Niels Ferguson, Reid Borsuk, Jeffrey Cooperstein, Matthew Ellis MIT
MurmurHash 3.0 Austin Appleby None
SipHash 1.0 Jean-Philippe Aumasson, Daniel J. Bernstein CC0 1.0
SuperFastHash - Paul Hsieh LGPL 2.1
WyHash final 3 Wang Yi None
xxHash 0.8.1 Yann Collet BSD 2-Clause

Implementation status

The table below gives an overview of the implementations.

Name Managed Unsafe 32bit 64bit 128bit Index Seeded Secret Verified
CityHash x x x x x x x x
DJBHash x x x x x
FarmHash x x x x x x -
FarshHash x x x x x
FNVHash x x x x x
HighwayHash x x x x
MarvinHash x x x x
MurmurHash x x x x x x -
SipHash x x x x x
SuperFastHash x x x
WyHash x x x x x
xxHash2 x x x x x x x
xxHash3 x x x x x x x
  • Managed: The there is a fully managed implementation in C#.
  • Unsafe: There is an unmanaged implementation that uses pointers etc. These are usually faster.
  • Bits: 32bit means there is a 32bit optimized implementation that returns an uint. 64bit means optimized for 64bit platforms.
  • Index: It has an index version, which½ can hash a 32/64bit integer directly. Usually used for Hash Table mapping.
  • Seeded: It takes an input seed which can help prevent denial-of-service due to hash collisions.
  • Secret: It supports a user-provided secret. Much like seeded version it protects against DoS attacks, but with stronger security guarantees.
  • Verified: The original author has provided test vectors and they have been tested against the implementation. A '-' means test vectors exist, but not yet implemented.


Hash functions

Measured on 32 MB data. The unsafe versions are implemented using C# unsafe code.

Note: Speed is not everything. The quality of a hash is just as important, but much more difficult to measure. See SMHasher for more details on hash quality.

Hash method MB/s
Wy3Hash64Unsafe 15.909
Wy3Hash64 15.256
Xx2Hash64Unsafe 13.374
Xx3Hash128Unsafe 12.582
CityHash128Unsafe 12.558
Xx2Hash64 12.438
CityHash64Unsafe 12.424
Xx3Hash64Unsafe 12.418
CityHash128 10.630
CityHash64 9.047
Xx2Hash32Unsafe 8.128
FarmHash64 8.089
FarmHash64Unsafe 7.987
Murmur3Hash128 7.982
Murmur3Hash128Unsafe 7.356
Xx2Hash32 7.287
FarmHash32Unsafe 7.233
FarshHash64Unsafe 7.186
FarmHash32 6.621
CityHash32Unsafe 6.433
CityHash32 5.712
Murmur3Hash32 3.796
Murmur3Hash32Unsafe 3.760
FarshHash64 3.474
SuperFastHash32 3.304
SuperFastHash32Unsafe 3.259
MarvinHash32 3.135
SipHash64Unsafe 2.581
SipHash64 2.576
Djb2Hash32 1.451
Djb2Hash64 1.448
Djb2Hash64Unsafe 1.447
Djb2Hash32Unsafe 1.444
Fnv1aHash32 1.092
Fnv1aHash32Unsafe 1.092
Fnv1aHash64Unsafe 1.092
Fnv1aHash64 1.079
Index functions
Method Mean Error StdDev
Fnv1aHash32 0.4503 ns 0.0227 ns 0.0213 ns
Xx2Hash32 0.5403 ns 0.0155 ns 0.0130 ns
Djb2Hash32 0.6525 ns 0.0311 ns 0.0275 ns
FarmHash64 0.6587 ns 0.0354 ns 0.0421 ns
Murmur3Hash32 0.6738 ns 0.0143 ns 0.0126 ns
Xx2Hash64 1.0247 ns 0.0428 ns 0.0379 ns
SuperFastHash32 1.0324 ns 0.0479 ns 0.0448 ns
MarvinHash32 1.1625 ns 0.0214 ns 0.0190 ns
CityHash64 1.2441 ns 0.0555 ns 0.0639 ns
Djb2Hash64 2.3256 ns 0.0743 ns 0.0966 ns
CityHash32 2.9076 ns 0.0770 ns 0.0682 ns
Fnv1aHash64 2.9311 ns 0.0873 ns 0.0934 ns
FarmHash32 2.9699 ns 0.0828 ns 0.0775 ns
Wy3Hash64 3.0273 ns 0.0675 ns 0.0632 ns
SipHash64 10.4360 ns 0.1979 ns 0.1851 ns
Mixer functions
Method Mean Error StdDev
FastHash_64 0.8871 ns 0.0281 ns 0.0249 ns
Murmur_32 0.8982 ns 0.0343 ns 0.0287 ns
Xmx_64 0.9057 ns 0.0379 ns 0.0336 ns
Murmur_32_Seed 0.9305 ns 0.0229 ns 0.0203 ns
XXH2_32_Seed 0.9482 ns 0.0317 ns 0.0281 ns
XXH2_32 0.9487 ns 0.0470 ns 0.0541 ns
MoreMur_64 0.9561 ns 0.0389 ns 0.0364 ns
Murmur_64 0.9569 ns 0.0500 ns 0.0614 ns
Murmur_32_SeedMix 1.0322 ns 0.0507 ns 0.1144 ns
XXH2_32_SeedMix 1.1050 ns 0.0308 ns 0.0273 ns
Murmur14_64 1.1320 ns 0.0175 ns 0.0163 ns
XXH2_64 1.1555 ns 0.0212 ns 0.0188 ns
Mx3_64 1.3364 ns 0.0320 ns 0.0284 ns
Xmx_64_Seed 1.3795 ns 0.0468 ns 0.0437 ns
Nasam_64 1.3889 ns 0.0233 ns 0.0207 ns
Murmur_64_Seed 1.4960 ns 0.0507 ns 0.0474 ns
Murmur14_64_SeedMix 1.5502 ns 0.0337 ns 0.0282 ns
Xmx_64_SeedMix 1.5543 ns 0.0249 ns 0.0221 ns
FastHash_64_SeedMix 1.5654 ns 0.0413 ns 0.0345 ns
XXH2_64_Seed 1.5730 ns 0.0286 ns 0.0254 ns
Murmur14_64_Seed 1.5763 ns 0.0356 ns 0.0315 ns
MoreMur_64_SeedMix 1.5887 ns 0.0209 ns 0.0174 ns
MoreMur_64_Seed 1.5952 ns 0.0563 ns 0.0526 ns
XXH2_64_SeedMix 1.6038 ns 0.0280 ns 0.0249 ns
Nasam_64_SeedMix 1.6203 ns 0.0610 ns 0.0509 ns
Nasam_64_Seed 1.6231 ns 0.0477 ns 0.0446 ns
Murmur_64_SeedMix 1.6244 ns 0.0273 ns 0.0242 ns
FastHash_64_Seed 1.6737 ns 0.0615 ns 0.0732 ns
City_64_Seed 1.6955 ns 0.0625 ns 0.1218 ns
Mx3_64_Seed 1.8109 ns 0.0653 ns 0.1092 ns
Mx3_64_SeedMix 1.8354 ns 0.0483 ns 0.0537 ns
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 is compatible.  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 was computed.  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)
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Version Downloads Last updated
1.0.0-alpha.3 226 12/3/2023
1.0.0-alpha.2 119 4/24/2023
1.0.0-alpha.1 111 1/9/2023