CloneBox
Benchmarks
CloneBox is the only library in the suite that gets every graph right — including cloning into an object you already have.
How we measure
CloneBox.Benchmark compares CloneBox with widely used clone libraries (DeepCloner, FastDeepCloner, CloneExtensions, AnyClone) and, as contrast, Mapster, AutoMapper, and a Newtonsoft.Json round-trip. Each (library × scenario) runs in an isolated process so a stack overflow cannot take down the suite.
Four graphs:
| # | Scenario | What it checks |
|---|---|---|
| 1 | simple | Typed POCO, primitives, list, nested child · 1,000,000 clones |
| 2 | cyclic | 301 children in List/Array/Dictionary (int keys), byte[], SelfReference · 400 clones |
| 3 | dynamic | ExpandoObject as root: typed class, nested Expando, Parent/Self cycles · 300,000 clones |
| 4 | into | Expando → existing DTO: matching members, keep extra target fields, skip [DoNotClone] · 200,000 runs |
Representative results
Release / net10.0 (times vary by machine):
| Library | simple | cyclic | dynamic | into | |
|---|---|---|---|---|---|
| CloneBox | 0.35 µs | 0.33 ms | 1.92 µs | 0.91 µs | 4/4 |
| DeepCloner | 0.20 µs | 0.37 ms | 1.18 µs | — | 3/4 |
| FastDeepCloner | 2.76 µs | — | — | — | 1/4 |
| CloneExtensions | 0.17 µs | — | — | — | 1/4 |
| AnyClone | 3.40 µs | — | — | — | 1/4 |
| Mapster | 0.36 µs | — | — | — | 1/4 |
| AutoMapper | 0.16 µs | — | — | — | 1/4 |
| Newtonsoft.Json | 2.31 µs | — | — | — | 1/4 |
A time is only listed when the result passed the checks — — means the copy was wrong or the process crashed.
Reproduce with:
dotnet run --project CloneBox.Benchmark -c ReleaseTakeaway
DeepCloner is a solid same-type cloner and wins on simple graphs. Mappers and serializers were never meant to be cloners. CloneBox is the one that is correct on cycles, on dynamic objects, and on clone-into.
Full write-up: GitHub README.