ArduinoJson

Pros of nlohmann/json

• More feature-rich and versatile, supporting a wider range of JSON operations
• Better performance for large JSON datasets
• Extensive documentation and examples

Cons of nlohmann/json

• Larger library size, which may be an issue for memory-constrained devices
• Steeper learning curve due to more complex API
• Not specifically optimized for embedded systems like Arduino

Code Comparison

ArduinoJson:

StaticJsonDocument<200> doc;
doc["sensor"] = "gps";
doc["time"] = 1351824120;
String output;
serializeJson(doc, output);

nlohmann/json:

json j;
j["sensor"] = "gps";
j["time"] = 1351824120;
std::string output = j.dump();

Both libraries offer similar basic functionality for creating and serializing JSON objects. However, nlohmann/json provides more advanced features and flexibility for complex JSON operations, while ArduinoJson is optimized for embedded systems with limited resources.

Pros of rapidjson

• Higher performance and lower memory usage
• Support for more advanced JSON features (e.g., UTF-8/16/32, int64)
• Better suited for large-scale applications and complex JSON structures

Cons of rapidjson

• Steeper learning curve and more complex API
• Less suitable for resource-constrained environments like Arduino
• Requires C++11 or later, limiting compatibility with older systems

Code Comparison

ArduinoJson:

StaticJsonDocument<200> doc;
doc["sensor"] = "gps";
doc["time"] = 1351824120;
String output;
serializeJson(doc, output);

rapidjson:

rapidjson::Document doc;
doc.SetObject();
doc.AddMember("sensor", "gps", doc.GetAllocator());
doc.AddMember("time", 1351824120, doc.GetAllocator());
rapidjson::StringBuffer buffer;
rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
doc.Accept(writer);
std::string output = buffer.GetString();

ArduinoJson is designed for simplicity and ease of use, particularly in embedded systems. It offers a more straightforward API and better integration with Arduino-specific features. rapidjson, on the other hand, provides higher performance and more advanced features, making it more suitable for larger-scale applications and complex JSON processing tasks. The code comparison illustrates the difference in complexity between the two libraries, with ArduinoJson offering a more concise and intuitive approach.

Pros of JsonCpp

• More comprehensive and feature-rich for general C++ applications
• Better support for complex JSON structures and advanced parsing
• Wider platform compatibility beyond Arduino environments

Cons of JsonCpp

• Larger memory footprint and higher resource usage
• More complex API, potentially steeper learning curve
• Not optimized for embedded systems or microcontrollers

Code Comparison

ArduinoJson:

StaticJsonDocument<200> doc;
deserializeJson(doc, jsonString);
String name = doc["name"];
int age = doc["age"];

JsonCpp:

Json::Value root;
Json::Reader reader;
reader.parse(jsonString, root);
std::string name = root["name"].asString();
int age = root["age"].asInt();

Both libraries offer JSON parsing capabilities, but ArduinoJson is more streamlined for embedded systems, while JsonCpp provides a more robust solution for general C++ applications. ArduinoJson's API is simpler and more memory-efficient, making it ideal for Arduino and other microcontroller projects. JsonCpp, on the other hand, offers more advanced features and better handles complex JSON structures, making it suitable for larger-scale applications on various platforms.

Pros of simdjson

• Extremely fast JSON parsing, optimized for modern CPUs
• Supports parsing gigabytes of JSON per second
• Designed for high-performance applications and big data processing

Cons of simdjson

• Not specifically designed for embedded systems or microcontrollers
• Higher memory footprint compared to ArduinoJson
• Steeper learning curve for beginners

Code Comparison

ArduinoJson:

StaticJsonDocument<200> doc;
deserializeJson(doc, jsonString);
const char* sensor = doc["sensor"];
long time = doc["time"];
double latitude = doc["data"][0];

simdjson:

ondemand::parser parser;
ondemand::document doc = parser.iterate(jsonString);
string_view sensor = doc["sensor"];
int64_t time = doc["time"];
double latitude = doc["data"].at(0);

Summary

ArduinoJson is tailored for Arduino and embedded systems, offering a user-friendly API and efficient memory usage. simdjson, on the other hand, focuses on high-performance JSON parsing for modern CPUs, making it ideal for big data applications. While simdjson excels in speed, ArduinoJson is more suitable for resource-constrained environments and provides an easier learning curve for beginners.

Pros of nativejson-benchmark

• Focuses on benchmarking multiple JSON libraries, providing comprehensive performance comparisons
• Supports a wide range of JSON libraries and parsing techniques
• Offers detailed performance metrics and analysis tools

Cons of nativejson-benchmark

• Not designed for direct use in Arduino projects, unlike ArduinoJson
• Lacks the simplicity and ease of integration that ArduinoJson provides for embedded systems
• May have a steeper learning curve for users primarily interested in JSON parsing for Arduino

Code Comparison

ArduinoJson:

StaticJsonDocument<200> doc;
deserializeJson(doc, jsonString);
String name = doc["name"];
int age = doc["age"];

nativejson-benchmark (using RapidJSON as an example):

Document d;
d.Parse(jsonString);
std::string name = d["name"].GetString();
int age = d["age"].GetInt();

While both libraries can parse JSON, ArduinoJson is specifically optimized for Arduino and embedded systems, offering a more straightforward API. nativejson-benchmark, on the other hand, focuses on benchmarking various JSON libraries and provides a platform for performance comparison rather than being a standalone JSON parsing solution.