ArduinoJson

Benchmarks in the README show it's twice smaller and 10% faster than the official Arduino_JSON library, with lower RAM consumption, crucial for resource-constrained embedded systems.

Header-only library compatible with C++11 to C++17, works on virtually any board from Arduino Uno to ESP32, and integrates with all major IDEs and toolchains like PlatformIO and Arduino IDE.

Handles both JSON and MessagePack serialization/deserialization, providing flexibility for compact data transmission in IoT devices, as highlighted in the features list.

Supports custom allocators, readers, writers, and converters, allowing integration with external RAM chips or specific data types, enhancing versatility for unique embedded scenarios.

Near 100% test coverage, continuous fuzzing, and comprehensive tutorials, examples, and a book ensure reliability and ease of learning, as documented in the README.