Open-source alternatives to Moshi

Fastjson is a Java data binding framework and serialization library designed to convert objects to JSON strings and parse JSON data into typed objects. It functions as a JSON parser and stream processor capable of transforming JSON strings into data structures. The project emphasizes high performance JSON processing and memory management, specifically through the use of a pipeline to stream oversized JSON objects and texts to prevent memory exhaustion. It provides capabilities for JSON data serialization and deserialization workflows, including custom JSON data mapping and the ability to def

MJExtension is a JSON serialization library and model mapping framework used to convert data between JSON strings and structured model objects. It functions as an object data mapper that handles the encoding and decoding of complex object hierarchies for network transmission and storage. The framework is a non-intrusive data mapper that uses reflection and runtime inspection to map raw data strings to application objects. This approach allows for data transformation without requiring base class inheritance, decorators, or extensions to the underlying model classes. The system supports recurs

HandyJSON is a Swift JSON serialization library and data mapper. It functions as an object mapper that converts JSON data into typed Swift models and transforms Swift objects back into JSON strings for storage or transmission. The library uses reflection to automatically map JSON keys to object properties and supports custom mapping metadata to resolve naming differences between APIs and code. It provides capabilities for extracting values from deep nested paths within a JSON structure and supports the transformation of complex types such as dates and URLs. The framework handles both the des

ObjectMapper is a JSON serialization framework for Swift that maps JSON strings and dictionaries into strongly typed classes and structs. It functions as a data mapper and converter, facilitating the bidirectional transformation of data between raw JSON and Swift model objects. The library uses protocol-based mapping to associate specific JSON keys with object properties. It supports nested key extraction via dot-notation pathing and employs custom transformation classes to bridge the gap between JSON and Swift types. The framework provides capabilities for model validation during initializa

This library is a high-performance JSON processing tool for Java designed to handle data serialization and deserialization with minimal resource consumption. It provides a framework for transforming complex object graphs into JSON strings and mapping raw input directly to typed class properties. The library distinguishes itself by utilizing compile-time code generation and reflection-free mapping to eliminate expensive runtime overhead. By employing iterator-based stream parsing and zero-allocation buffer management, it processes large or deeply nested data structures while reducing garbage c

YYModel is a JSON model mapping library and bidirectional data mapper designed to transform raw JSON data into structured model objects and vice versa. It functions as a type-safe JSON parser that employs automatic type coercion to prevent application crashes caused by incompatible data types during the parsing process. The framework uses runtime introspection to map JSON keys to model properties based on naming rules and explicit configurations. It supports the instantiation of nested model objects through recursive traversal of the data hierarchy and provides a consistent translation layer

cJSON is a lightweight library for parsing, creating, and modifying JSON data structures within C applications. It provides a comprehensive set of utilities for transforming raw text into navigable objects, manipulating data fields within collections, and serializing complex structures into formatted or unformatted strings. The library is designed for memory-sensitive and resource-constrained environments, utilizing manual memory management and type-tagged union structures to maintain a minimal footprint. It employs recursive descent parsing and in-place string manipulation to process data ef

This project is a framework for the efficient serialization and deserialization of data structures. It provides a unified, macro-based interface that automates the conversion of complex internal objects into standardized formats and reconstructs them from raw input streams or buffers. By leveraging compile-time code generation, the library minimizes manual implementation overhead while ensuring consistent logic across diverse data types. The framework distinguishes itself through a format-agnostic data model and a visitor-based parsing architecture that decouples data structures from specific

JSONKit is an Objective-C library used for parsing, serializing, and manipulating JSON data. It functions as a JSON parser that converts text into native data structures and a serializer that transforms native objects into formatted JSON text. The library includes a gzip compression wrapper that compresses serialized JSON payloads to reduce network transfer sizes and automatically detects and decompresses gzip buffers before decoding. The toolset provides capabilities for JSON parsing and serialization, supporting customizable indentation, character escaping, and flexible comment handling.

easyjson is a high-performance JSON serializer and memory-optimized parser for Go. It provides a reflectionless code generator that creates static Go methods for marshaling and unmarshaling data, eliminating the need for runtime reflection to improve execution speed. The library reduces CPU and memory overhead through several optimization strategies. It employs a system of reusable memory buffer pools to minimize heap allocations and garbage collection pressure. Additionally, it utilizes string interning to deduplicate repeated values and zero-copy string referencing to point to existing buff

This project is a high-performance JSON library for Go, serving as a replacement for the standard encoding/json package. It provides a serialization engine for encoding and decoding data structures, alongside a schemaless parser for extracting specific values from JSON blobs using paths. The library distinguishes itself through a focus on reducing CPU and memory overhead. It implements a high-performance encoder that utilizes buffer reuse and reduced float precision to increase data throughput. Broad capability areas include data serialization, high-performance JSON processing, and schema-le

This project is a comprehensive sample library and implementation guide for ASP.NET Core. It provides a collection of practical examples and projects that demonstrate how to build web applications, RESTful APIs, and high-performance services. The repository focuses on a variety of architectural patterns, including the development of Minimal APIs, contract-first gRPC services, and real-time communication using WebSockets and Server-Sent Events. It includes detailed implementations for user identity and security, such as token-based authentication and CSRF protection. The codebase covers a bro

Sonic is a high-performance Go JSON serialization library that provides tools for encoding and decoding native data structures. It functions as a JIT-accelerated encoder, a JSON AST parser, a stream processor, and a lazy decoder. The project utilizes just-in-time machine code generation to optimize the encoding of large data schemas and employs a JIT assembler to maximize serialization and deserialization speeds. It features a precompiled schema warmup process to prevent latency spikes during initial execution and leverages SIMD hardware instructions for accelerated parsing. The library cove

JsonPath is a Java library designed for querying and manipulating JSON documents using the JsonPath expression language. It functions as a query engine for extracting and filtering specific data from JSON structures through path-based expressions. The library provides capabilities for transforming JSON documents by modifying values or mapping extracted data into Java objects. It also includes an aggregation library for calculating statistical metrics, such as sums and averages, on numeric arrays. The project handles data extraction through array filtering and numerical aggregation. Performan

yyjson is a high-performance C library for parsing, serializing, and manipulating JSON data structures. It functions as a memory-efficient data tool that utilizes custom memory pools and contiguous block allocation to minimize fragmentation and overhead. The project distinguishes itself as a SIMD JSON processor, using hardware-accelerated vector instructions for rapid string validation and parsing. It provides a toolkit for querying, modifying, and patching nested JSON objects and arrays through pointer-based access and path expressions. The library covers a broad range of data manipulation

RapidJSON is a header-only C++ library designed for high-performance parsing, generation, and manipulation of JSON data. It functions as a dual-mode engine, providing both an in-memory document object model for tree-based manipulation and a stream-based interface for event-driven processing. The library is built to minimize memory footprint and maximize execution speed, making it suitable for resource-constrained environments. The library distinguishes itself through advanced memory management and optimization techniques, including in-situ parsing that modifies input buffers directly to elimi

gjson is a Go JSON parser designed for schema-less reading and value extraction. It allows for the retrieval of specific data from JSON documents using dot-notation paths without requiring the definition of predefined Go structs. The library provides tools for path-based querying, including the use of wildcards and index-based queries to locate data within objects and arrays. It also functions as a JSON lines processor, treating multi-line documents as arrays to iterate and query individual entries. Additional capabilities include converting JSON values into native Go types such as strings,

JSONModel is a data modeling framework and serialization library for Apple platforms, including iOS, macOS, watchOS, and tvOS. It transforms JSON strings and dictionaries into typed Swift objects to eliminate manual dictionary parsing. The framework provides a mapping system that utilizes custom key rules and dot-notation to resolve nested data hierarchies. It supports the conversion of complex JSON structures into organized model relationships and manages the transformation of JSON arrays into collections of typed model instances. The toolset includes data type transformation via custom tra

Ajv is a high-performance data validation framework that compiles JSON schemas into optimized, standalone JavaScript functions. By transforming declarative schema definitions into executable code, it eliminates runtime interpretation overhead and provides a secure, efficient way to enforce data integrity across both browser and server environments. The library distinguishes itself through its focus on performance and type safety. It employs advanced compilation techniques, including abstract syntax tree optimization and function caching, to ensure rapid validation. Beyond standard checks, it

This is a JavaScript library for parsing and serializing JSON data, with a particular focus on handling objects that contain circular references. It provides a standard JSON parser that reads text and reconstructs JavaScript values without using the eval function, guarding against code injection, alongside a standard serializer that converts objects into JSON strings for data interchange. The library distinguishes itself by offering specialized encoding and decoding for cyclical object graphs. It can serialize objects with circular references by replacing repeated object paths with JSONPath s

This is a Rust serialization library for converting data structures to and from JSON strings and byte streams. It is built as a framework within the Serde ecosystem, providing both a strongly typed parser for compile-time safety and a recursive value tree for manipulating JSON data without a predefined schema. The project supports both typed and untyped processing. It can map JSON data into specific Rust types for schema conformity or parse input into a flexible, schemaless representation. It also includes macro-based utilities for the dynamic construction of JSON objects.

The C++ REST SDK is a library for asynchronous HTTP and RESTful communication in native C++ applications. It provides a non-blocking network client for sending requests and receiving responses, a JSON parser for serializing and deserializing data, and a WebSocket client library for real-time, full-duplex communication. The project includes a dedicated OAuth2 authentication client to manage access tokens and authorization flows for secure communication with protected cloud resources. It utilizes a task-based asynchronous model to coordinate background operations and keep application interfaces

node-fs-extra is a Node.js file system extension that provides a set of additional methods to simplify common file and directory operations. It functions as a recursive directory manager, a JSON file processor, and a file asset manipulator, extending the standard library to provide high-level utilities for managing assets on disk. The project distinguishes itself through recursive capabilities, such as duplicating or removing nested folder structures and ensuring that all missing parent directories are automatically generated when creating files or symbolic links. It also integrates a JSON se

ArduinoJson is a C++ library for parsing and manipulating JSON data and MessagePack binary streams on microcontrollers with limited memory and processing power. It provides the core primitives necessary for embedded data serialization and parsing, enabling devices to exchange structured data over serial or network interfaces. The library is distinguished by its focus on microcontroller memory management, employing strategies such as pool-based allocation, string deduplication, and non-owning string views to minimize RAM usage. It further optimizes for constrained environments by allowing cons

RestSharp is a .NET HTTP client library designed for interacting with RESTful web services. It provides a high-level request wrapper and a dedicated REST API client to manage endpoints, headers, and query parameters. The library includes a serialization mechanism that automatically converts objects to and from JSON or XML formats for API payloads. It also features a system for managing API credentials and security tokens to ensure authorized access to protected remote resources. The toolkit covers broad capabilities for external web service integration, including generic type-based deseriali

simdjson is a high-performance, header-only C++ library designed for parsing, querying, and serializing JSON data with minimal memory overhead. It functions as a hardware-aware data processing engine that leverages vector instructions to achieve gigabyte-per-second parsing speeds. By detecting host processor capabilities at runtime, the library automatically selects the most efficient instruction sets to accelerate structural analysis and validation. The library distinguishes itself through a focus on extreme efficiency and resource management. It utilizes memory mapping and padded buffer ali

RapidJSON is a high-performance C++ library used for parsing and generating JSON data. It provides both document object model and stream-based interfaces to transform JSON strings into structured data and vice versa. The library includes a JSON schema validator to verify that documents conform to predefined rules and a Unicode transcoder for converting strings between UTF-8, UTF-16, and UTF-32 encodings. It also supports relaxed parsing for non-standard JSON containing comments or trailing commas. Additional capabilities cover JSON pointer navigation for locating specific values and string s