How fast is Jil compared to Json.NET?

Jil is significantly faster, often 2-3x quicker in serialization and deserialization benchmarks due to IL generation and low-level optimizations. However, this speed comes at the cost of reduced flexibility and type support compared to Json.NET.

How to handle dynamic JSON with Jil?

Use the JSON.SerializeDynamic and JSON.DeserializeDynamic methods for unknown types at runtime. These support operations like member access, casts, and foreach loops, but note that dynamic handling may be slower than static typing and has limitations in type inference.

Does Jil support .NET Core or .NET 5+?

Jil primarily targets .NET Framework, but check NuGet for compatibility with .NET Core and later versions. Some optimizations may require adjustments, and community support might be limited compared to mainstream libraries.

What types does Jil not support?

Jil does not support arbitrary .NET types; unsupported cases include custom collections not implementing IList , complex object graphs with circular references, and types requiring extensive custom serialization beyond DataMember or JilDirective attributes.

How to configure date formats in Jil?

Pass an Options parameter to serialize/deserialize methods, specifying formats like ISO8601, Unix epoch, or Microsoft style. For example, use Options.ISO8601 for standard date strings, and note that DateTimes are serialized as UTC by default for round-tripping.

Is Jil case sensitive when deserializing?

Yes, Jil is case-sensitive by default, so member names must match the JSON exactly. Use the camelCase configuration option or JilDirective attributes to handle different naming conventions without manual mapping.

Can Jil serialize inherited members?

Yes, but only if configured; set the IncludeInherited option in Options to include inherited public fields and properties during serialization. By default, it may exclude them unless explicitly enabled.

Jil — High-Performance .NET JSON Serializer

What is Jil?

Jil is a high-performance JSON serializer and deserializer library for .NET, built on the Sigil library for IL generation. It focuses on achieving maximum speed through low-level optimizations, custom formatting, and minimal memory allocation, making it significantly faster than many general-purpose JSON libraries in .NET.

Target Audience

.NET developers working on performance-sensitive applications where JSON serialization/deserialization throughput is critical, such as high-traffic web APIs, microservices, or data processing pipelines.

Value Proposition

Developers choose Jil for its exceptional speed, achieved through IL generation, optimized member ordering, and avoidance of unnecessary allocations. It outperforms popular alternatives like Json.NET and ServiceStack.Text in benchmarks, making it the go-to choice when performance is the top priority.

Fast .NET JSON (De)Serializer, Built On Sigil

Use Cases

Best For

High-throughput web APIs requiring fast JSON serialization
Microservices where low latency in JSON processing is critical
Data processing pipelines that serialize/deserialize large volumes of JSON
Performance-sensitive applications where JSON speed is a bottleneck
Scenarios requiring configurable date/time formatting in JSON
Projects needing dynamic serialization/deserialization of unknown types

Not Ideal For

Applications requiring serialization of arbitrary .NET types not explicitly supported by Jil, such as custom collections or complex object graphs.
Projects where JSON fields may contain union types that cannot be distinguished by their first character, limiting polymorphic handling.
Scenarios needing guaranteed member serialization order or advanced JSON manipulation features like schema validation.
Teams prioritizing out-of-the-box compatibility with all .NET frameworks without performance tuning or 'priming' setup.

Pros & Cons

Pros

Blazing Fast Serialization

Leverages Sigil for IL generation and low-level optimizations like custom number formatting, achieving 2-3x speed gains over Json.NET in benchmarks for supported types.

Configurable Date/Time Handling

Supports multiple formats including ISO8601, Unix epoch, and RFC1123, allowing flexible JSON date representations without sacrificing performance.

Dynamic Type Support

Includes SerializeDynamic and DeserializeDynamic methods for handling unknown types at runtime, with operations like member access and casts for JSON objects and arrays.

Memory Efficiency

Minimizes GC pressure by reusing buffers and avoiding reference type allocations where possible, crucial for high-throughput applications.

Cons

Limited Type Compatibility

Only supports a predefined list of types; complex or user-defined types not composed of supported ones will fail or require workarounds, restricting flexibility.

First-Use Performance Hit

Initial serialization/deserialization per type-config pair incurs overhead for IL generation, requiring 'priming the pump' for consistent low latency in production.

Restrictive Union Support

Union types are only allowed if distinguishable by first character, making it unsuitable for JSON with polymorphic fields that share initial characters like numbers.

Case Sensitivity and Order Issues

Deserialization is case-sensitive by default and member serialization order is not guaranteed, which can lead to subtle bugs if naming conventions or order dependencies exist.

What is Jil?

Target Audience

Value Proposition

Use Cases

Best For

High-throughput web APIs requiring fast JSON serialization
Microservices where low latency in JSON processing is critical
Data processing pipelines that serialize/deserialize large volumes of JSON
Performance-sensitive applications where JSON speed is a bottleneck
Scenarios requiring configurable date/time formatting in JSON
Projects needing dynamic serialization/deserialization of unknown types

Not Ideal For

Applications requiring serialization of arbitrary .NET types not explicitly supported by Jil, such as custom collections or complex object graphs.
Projects where JSON fields may contain union types that cannot be distinguished by their first character, limiting polymorphic handling.
Scenarios needing guaranteed member serialization order or advanced JSON manipulation features like schema validation.
Teams prioritizing out-of-the-box compatibility with all .NET frameworks without performance tuning or 'priming' setup.

Pros & Cons

Pros

Blazing Fast Serialization

Leverages Sigil for IL generation and low-level optimizations like custom number formatting, achieving 2-3x speed gains over Json.NET in benchmarks for supported types.

Configurable Date/Time Handling

Supports multiple formats including ISO8601, Unix epoch, and RFC1123, allowing flexible JSON date representations without sacrificing performance.

Dynamic Type Support

Includes SerializeDynamic and DeserializeDynamic methods for handling unknown types at runtime, with operations like member access and casts for JSON objects and arrays.

Memory Efficiency

Minimizes GC pressure by reusing buffers and avoiding reference type allocations where possible, crucial for high-throughput applications.

Cons

Limited Type Compatibility

Only supports a predefined list of types; complex or user-defined types not composed of supported ones will fail or require workarounds, restricting flexibility.

First-Use Performance Hit

Initial serialization/deserialization per type-config pair incurs overhead for IL generation, requiring 'priming the pump' for consistent low latency in production.

Restrictive Union Support

Union types are only allowed if distinguishable by first character, making it unsuitable for JSON with polymorphic fields that share initial characters like numbers.

Case Sensitivity and Order Issues

Deserialization is case-sensitive by default and member serialization order is not guaranteed, which can lead to subtle bugs if naming conventions or order dependencies exist.

Jil

What is Jil?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

Jil

What is Jil?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?