Features

• Serializes in the compact and fast MessagePack format.
• No attributes required on your data types. Optional attributes allow customization and improve performance.
• Supports the latest C# syntax including required and init properties, record classes and structs, and primary constructors.
• This library is perf-optimized and is among the fastest MessagePack serialization libraries available for .NET.
• Works great in your NativeAOT, trimmed, SignalR or ASP.NET Core MVC applications or Unity games.
• Many C# analyzers to help you avoid common mistakes.
• Great security for deserializing untrusted data.
• Polymorphic deserialization lets you deserialize derived types.
• True async and streaming deserialization for large or over-time sequences keeps your apps responsive and memory pressure low.
• Preserve reference equality across serialization/deserialization (optional).
• Forward compatible data retention allows you to deserialize and re-serialize data without dropping properties you didn't know about.
• Structural equality checking and hashing for arbitrary types gives you deep by-value equality semantics without hand-authoring Equals and GetHashCode overrides.
• No mutable statics ensures your code runs properly no matter what other code might run in the same process.
• Only serialize properties with non-default values (optional).
• Primitive msgpack reader and writer APIs for low-level scenarios.
• Author custom converters for advanced scenarios.

Feature comparison

See how this library compares to other .NET MessagePack libraries.

In many cases, the ✅ or ❌ in the table below are hyperlinks to the relevant documentation or an issue you can vote up to request the feature.

Feature	Nerdbank.MessagePack	MessagePack-CSharp	Serde.NET
Optimized for high performance	✅	✅	✅
Contractless data types	✅1	✅	❌
Attributed data types	✅	✅	✅
Polymorphic serialization	✅	✅2	✅
Duck-typed polymorphic serialization	✅	❌	❌
F# union type support	✅	❌	❌
Typeless serialization	✅	✅	❌
dynamic serialization	✅	✅	❌
Forward compatible data retention	✅	❌	❌
Property name transformations	✅	❌	❌
Skip serializing default values	✅	❌	🌗
Required and non-nullable property deserialization guaranteed	✅	❌	✅
Dynamically use maps or arrays for most compact format	✅	❌	❌
Surrogate types for automatic serialization of unserializable types	✅	❌	✅
Custom converters	✅	✅	✅
Stateful converters	✅	❌	❌
Deserialization callback	✅	✅	❌
MsgPack extensions	✅	✅	❌
LZ4 compression	❌	✅	❌
Trim-safe	✅	❌	✅
NativeAOT ready	✅	❌3	✅
Unity	✅4	✅	❔
Async	✅	❌	❌
Endless streaming deserialization	✅	✅	❌
Reference preservation	✅	❌	❌
Cyclical references	✅	❌	❌
JSON schema export	✅	❌	❌
Secure defaults	✅	❌	❌
Automatic hash collection deserialization in secure mode	✅	✅	❌
Automatic collision-resistant hash function for arbitrary types	✅	❌	❌
Rejection of data that defines multiple values for the same property	✅	❌	❌
Free of mutable statics	✅	❌	✅
Structural IEqualityComparer<T> for arbitrary types	✅	❌	❌

Security is a complex subject. Learn more about how to secure your deserializer.

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1. Nerdbank.MessagePack's approach is more likely to be correct by default and more flexible to fixing when it is not.↩

2. MessagePack-CSharp is limited to derived types that can be attributed on the base type, whereas Nerdbank.MessagePack allows for dynamically identifying derived types at runtime.↩

3. Although MessagePack-CSharp does not support .NET 8 flavor NativeAOT, it has long-supported Unity's il2cpp runtime, but it requires careful avoidance of dynamic features.↩

4. See our unity doc for instructions.↩