KsuidDotNet

A high-performance, zero-allocation KSUID (Key Sortable Unique Identifier) generator for .NET 8 and .NET 10.

Designed for high-throughput database engines and distributed systems where unique ID generation is on the hot path.

🚀Performance

This library is engineered for speed. It uses hardware intrinsics, stackalloc, and a buffered RNG strategy to outperform standard implementations.

• creates crypto-random KSUID strings
• blazing-fast performance
• no additional memory overhead, memory allocation only for string
• thread-safe and lock-free
• targets .net 8, .net 10

Key Optimizations

• Zero Allocation: Uses string.Create and Span<T> to write directly to the heap, bypassing intermediate string allocations.

• Buffered RNG: Uses a thread-static buffer to amortize the cost of Syscall (randomness) overhead by ~99%.

• Math Intrinsics: Leverages modern .NET Math.DivRem and BinaryPrimitives to optimize the Base62 encoding loop.

installation

$ dotnet add package KsuidDotNet

how to use

Create a random KSUID:

string id = Ksuid.NewKsuid(); Console.WriteLine(id); // outputs 29faSiN1gPB6IzM74u6tMfTO02L

Creating a random KSUID string with the prefix c_:

string id = Ksuid.NewKsuid("c_"); Console.WriteLine(id); // outputs c_29faSiN1gPB6IzM74u6tMfTO02L

micro benchmarks

Benchmark results for KsuidDotNet and other KSUID libraries.

BenchmarkDotNet v0.15.6, macOS 26.1 (25B78) [Darwin 25.1.0] Apple M2 Max, 1 CPU, 12 logical and 12 physical cores .NET SDK 10.0.100 [Host] : .NET 10.0.0 (10.0.0, 10.0.25.52411), Arm64 RyuJIT armv8.0-a DefaultJob : .NET 10.0.0 (10.0.0, 10.0.25.52411), Arm64 RyuJIT armv8.0-a

Method	Mean	Error	StdDev	StdErr	Min	Q1	Median	Q3	Max	Op/s	Gen0	Allocated
KsuidDotNet_NewKsuid	212.9 ns	0.44 ns	0.39 ns	0.10 ns	212.2 ns	212.6 ns	212.8 ns	213.0 ns	213.6 ns	4,697,926.3	0.0095	80 B
KsuidDotNet_NewKsuid_WithPrefix	215.0 ns	0.35 ns	0.33 ns	0.08 ns	214.5 ns	214.8 ns	215.0 ns	215.2 ns	215.4 ns	4,651,593.6	0.0095	80 B
StructKsuid_RandomKsuidToString	399.2 ns	0.50 ns	0.45 ns	0.12 ns	398.2 ns	398.9 ns	399.3 ns	399.5 ns	399.7 ns	2,505,210.7	0.0095	80 B
StructKsuid_RandomKsuidToStringWithPrefix	410.8 ns	0.68 ns	0.64 ns	0.17 ns	409.4 ns	410.5 ns	410.8 ns	411.2 ns	412.0 ns	2,434,101.3	0.0191	160 B
DotKsuid_GenerateToString	432.4 ns	0.98 ns	0.87 ns	0.23 ns	430.8 ns	431.8 ns	432.5 ns	433.0 ns	433.6 ns	2,312,888.0	0.1516	1272 B
DotKsuid_GenerateToStringWithPrefix	438.7 ns	0.63 ns	0.59 ns	0.15 ns	437.6 ns	438.3 ns	438.7 ns	439.0 ns	439.8 ns	2,279,615.1	0.1612	1352 B
ksuid_GenerateToString	1,959.4 ns	5.88 ns	5.50 ns	1.42 ns	1,947.4 ns	1,956.0 ns	1,960.7 ns	1,963.4 ns	1,967.1 ns	510,368.8	0.9346	7824 B
ksuid_GenerateToStringWithPrefix	1,972.9 ns	5.97 ns	4.98 ns	1.38 ns	1,961.1 ns	1,972.1 ns	1,974.1 ns	1,975.4 ns	1,980.4 ns	506,877.3	0.9422	7904 B

license

This library is open-source software released under the MIT License.