FastGuid 1.3.0

There is a newer version of this package available.
See the version list below for details.
dotnet add package FastGuid --version 1.3.0
                    
NuGet\Install-Package FastGuid -Version 1.3.0
                    
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="FastGuid" Version="1.3.0" />
                    
For projects that support PackageReference, copy this XML node into the project file to reference the package.
<PackageVersion Include="FastGuid" Version="1.3.0" />
                    
Directory.Packages.props
<PackageReference Include="FastGuid" />
                    
Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package.
paket add FastGuid --version 1.3.0
                    
#r "nuget: FastGuid, 1.3.0"
                    
#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.
#addin nuget:?package=FastGuid&version=1.3.0
                    
Install as a Cake Addin
#tool nuget:?package=FastGuid&version=1.3.0
                    
Install as a Cake Tool

FastGuid NuGet

by Stan Drapkin

10 times faster than Guid.NewGuid()

  • High-performance, cryptographically strong GUID generation
  • Database-optimized GUIDs for SQL Server and PostgreSQL
  • Fast random byte filling
  • Fastest .NET random string generation

Install

dotnet add package FastGuid

Static APIs for GUIDs and random data generation

  • Guid FastGuid.NewGuid()
    • Returns a cryptographically random GUID.
    • ~10x (900%) faster than Guid.NewGuid().
  • FastGuid.Fill(Span<byte> data)
    • Fills a span with cryptographically strong random bytes.
    • ~1.5x (50%) to 9x (800%) faster for <512 bytes, otherwise calls RandomNumberGenerator.Fill()

Static APIs for SQL Server- and PostgreSQL-optimized GUIDs

  • Guid FastGuid.NewSqlServerGuid()

    • Returns a new Guid optimized for use as a SQL-Server clustered key.
    • Guid structure is [8 random bytes] [8 bytes of SQL-Server-ordered DateTime.UtcNow]
    • Each Guid is sequential across 100-nanosecond UtcNow precision limits.
    • 64-bit cryptographic randomness adds uniqueness for timestamp collisions and provides reasonable unguessability and protection against online brute-force attacks.
  • Guid FastGuid.NewPostgreSqlGuid()

    • Returns a new Guid optimized for use as a PostgreSQL primary key or index.
    • Guid structure is [8 bytes of PostgreSQL-ordered DateTime.UtcNow] [8 random bytes]
    • Each Guid is sequential across 100-nanosecond UtcNow precision limits.
    • 64-bit cryptographic randomness adds uniqueness for timestamp collisions and provides reasonable unguessability and protection against online brute-force attacks.
  • Helper methods for Guids generated by NewSqlServerGuid():

    • DateTime FastGuid.SqlServer.GetTimestamp(Guid guid)
      • Extracts SqlServer Guid creation timestamp (UTC). Full DateTime.UtcNow precision.
    • Guid FastGuid.SqlServer.MinGuidForTimestamp(DateTime timestampUtc)
    • Guid FastGuid.SqlServer.MaxGuidForTimestamp(DateTime timestampUtc)
      • Return the smallest/largest Guid for a given timestamp (useful for time-based SQL-Server range searches).
  • Helper methods for Guids generated by NewPostgreSqlGuid():

    • DateTime FastGuid.PostgreSql.GetTimestamp(Guid guid)
      • Extracts PostgreSQL Guid creation timestamp (UTC). Full DateTime.UtcNow precision.
    • Guid FastGuid.PostgreSql.MinGuidForTimestamp(DateTime timestampUtc)
    • Guid FastGuid.PostgreSql.MaxGuidForTimestamp(DateTime timestampUtc)
      • Return the smallest/largest Guid for a given timestamp (useful for time-based PostgreSQL range searches).

Static APIs for fast random string generation

  • string FastGuid.StringGen.Text16(int length)
    • Generates a random string using the Base16 (hex) alphabet.
  • string FastGuid.StringGen.Text32(int length)
    • Generates a random string using the Base32 alphabet (RFC 4648).
  • string FastGuid.StringGen.Text64(int length)
    • Generates a random string using the Base64 alphabet (RFC 4648).
  • string FastGuid.StringGen.Text64Url(int length)
    • Generates a random string using the Base64Url alphabet (RFC 4648, URL-safe).
  • All methods use cryptographically strong randomness and are suitable for passwords, tokens, keys, and identifiers.

Usage

Replace all calls to Guid.NewGuid() with FastGuid.NewGuid()

..from this:

Guid guid = Guid.NewGuid(); // your current code

..to this:

// using SecurityDriven;
Guid guid = FastGuid.NewGuid(); // 10x faster
  • Thread-safe
  • 128 bits of cryptographically strong randomness

Switch from this:

Span<byte> key = stackalloc byte[32];
RandomNumberGenerator.Fill(key); // 145 nanoseconds

..to this:

Span<byte> key = stackalloc byte[32];
FastGuid.Fill(key); // 20 nanoseconds (7x faster)

Guid.CreateVersion7() causes page-fragmentation in SQL-Server and PostgreSQL. DO NOT USE Guid.CreateVersion7() for database Guids. Yes, I have tested it with SQL-Server and PostgreSQL and it causes severe page-fragmentation. Use FastGuid.NewSqlServerGuid() or FastGuid.NewPostgreSqlGuid() instead. Internet advice to use Guid.CreateVersion7() for database Guids is wrong.

Benchmark #1:

public class Bench
{
	[Benchmark(Baseline = true)]
	public void FastGuid_NewGuid() // 12 calls
	{
		FastGuid.NewGuid(); FastGuid.NewGuid(); FastGuid.NewGuid(); FastGuid.NewGuid();
		FastGuid.NewGuid(); FastGuid.NewGuid(); FastGuid.NewGuid(); FastGuid.NewGuid();
		FastGuid.NewGuid(); FastGuid.NewGuid(); FastGuid.NewGuid(); FastGuid.NewGuid();
	}

	[Benchmark]
	public void Guid_NewGuid() // 12 calls
	{
		Guid.NewGuid(); Guid.NewGuid(); Guid.NewGuid(); Guid.NewGuid();
		Guid.NewGuid(); Guid.NewGuid(); Guid.NewGuid(); Guid.NewGuid();
		Guid.NewGuid(); Guid.NewGuid(); Guid.NewGuid(); Guid.NewGuid();
	}
}//class Bench
BenchmarkDotNet=v0.13.2, OS=Windows 10 (10.0.19045.2364)
Intel Core i7-10510U CPU 1.80GHz, 1 CPU, 8 logical and 4 physical cores
.NET SDK=7.0.101
  [Host] : .NET 7.0.1 (7.0.122.56804), X64 RyuJIT AVX2
Method Mean Error StdDev Ratio
FastGuid_NewGuid 116.6 ns 2.26 ns 5.19 ns 1.00
Guid_NewGuid 1,215.9 ns 23.85 ns 45.96 ns 10.39

Benchmark #2:

static Guid Guid_NewGuid() => Guid.NewGuid();
static Guid Guid_CreateVersion7() => Guid.CreateVersion7();
static Guid FastGuid_NewGuid() => SecurityDriven.FastGuid.NewGuid();
static Guid FastGuid_NewSqlServerGuid() => SecurityDriven.FastGuid.NewSqlServerGuid();
static Guid FastGuid_NewPostgreSqlGuid() => SecurityDriven.FastGuid.NewPostgreSqlGuid();
BenchmarkDotNet v0.13.8, Windows 10 (10.0.19045.5371/22H2/2022Update)
Intel Core i7-10510U CPU 1.80GHz, 1 CPU, 8 logical and 4 physical cores
.NET SDK 9.0.102
  [Host] : .NET 9.0.1 (9.0.124.61010), X64 RyuJIT AVX2
Method Mean Error StdDev Ratio
Guid_NewGuid 84.479 ns 1.5090 ns 3.3751 ns 9x
Guid_CreateVersion7 116.798 ns 1.5795 ns 1.8190 ns 12x
FastGuid_NewGuid 9.676 ns 0.2318 ns 0.5278 ns 1x
FastGuid_NewSqlServerGuid 36.710 ns 0.6097 ns 0.8546 ns 4x
FastGuid_NewPostgreSqlGuid 37.292 ns 0.7558 ns 1.0839 ns 4x

image

Example: Fast random string generation

// Generate a 16-character random hexadecimal string
string hex = FastGuid.StringGen.Text16(16); // 64 bits of entropy

// Generate a 32-character random Base32 session identifier
string sessionId = FastGuid.StringGen.Text32(32); // 160 bits of entropy

// Generate a 32-character random Base64Url token
string token = FastGuid.StringGen.Text64Url(32); // 192 bits of entropy

Benchmark #3: Fast random string generation

static Guid FastGuid_NewGuid() => FastGuid.NewGuid();
static string FastGuid_StringGen_Text16_16() => FastGuid.StringGen.Text16(16);
static string FastGuid_StringGen_Text32_32() => FastGuid.StringGen.Text32(32);
static string FastGuid_StringGen_Text64Url_32() => FastGuid.StringGen.Text64Url(32);
BenchmarkDotNet v0.13.8, Windows 10 (10.0.19045.5917/22H2/2022Update)
Intel Core i7-10510U CPU 1.80GHz, 1 CPU, 8 logical and 4 physical cores
.NET SDK 10.0.100-preview.5.25277.114
  [Host] : .NET 10.0.0 (10.0.25.27814), X64 RyuJIT AVX2

image

Product Compatible and additional computed target framework versions.
.NET net5.0 is compatible.  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.  net9.0 was computed.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed.  net10.0 was computed.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.
  • net5.0

    • No dependencies.

NuGet packages (1)

Showing the top 1 NuGet packages that depend on FastGuid:

Package Downloads
Oasis.Core.Common

Package Description

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Version Downloads Last Updated
1.4.1 153 7/2/2025
1.4.0 137 6/20/2025
1.3.0 436 6/13/2025
1.2.0 6,934 1/28/2025
1.1.0 1,544 9/4/2024
1.0.6 1,912 1/22/2024
1.0.5 170 10/5/2023
1.0.4 342 12/24/2022
1.0.1 402 8/30/2021
1.0.0 395 8/15/2021
1.0.0-alpha 260 8/14/2021

Performance improvements.
~10x faster than Guid.NewGuid().
Performance-tested on .NET 10, 9, 8, 7, 6, and 5.
New SqlServer Guid helper methods (timestamp extraction, range search) - see README.
New PostgreSQL Guid helper methods (timestamp extraction, range search) - see README.
New FastGuid.Fill() method for fast random byte generation - see README.
New FastGuid.StringGen APIs for fast, cryptographically strong random string generation (Base16, Base32, Base64, Base64Url) - see README.
Improved documentation.