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JSON → C++ Struct

Generate C++ structs from JSON (STL: std::string / std::vector)

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Generation Options
Input JSONJSON
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Generated resultC++
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Overview: The JSON → C++ Struct generator produces C++ struct definitions from a sample JSON payload, using standard-library types (std::string, std::vector) to represent strings and arrays. It gives C++ developers ready-made data structures for deserialisation libraries such as nlohmann/json, RapidJSON or Boost.PropertyTree.

How to use: Step 1 — paste sample JSON on the left, or click "Sample" to load a preset payload. Step 2 — specify the root struct name (default RootObject). Step 3 — the tool produces the corresponding struct definitions live; nested objects are split into their own structs and arrays uniformly use std::vector. Step 4 — copy the code into your project or download as a .h header. Combined with nlohmann/json you only need to include the header and most of the deserialisation is done.

Typical scenarios: C++ network service developers integrating HTTP JSON APIs; game engines (Unreal Engine, in-house engines) pulling configuration or protocol data from a server; embedded or IoT devices parsing JSON commands from the cloud; mapping interface protocols from Python / Node.js microservices into C++ clients; generating test-only data types from Postman captures.

Technical notes: Integers default to int, floats to double, booleans to bool, strings to std::string, arrays to std::vector<T>. Null or mixed types are represented with auto (consider replacing with std::optional or std::variant). Struct names are PascalCased. The generated header does not include #include statements, add them as needed. When using nlohmann/json we recommend manually adding the NLOHMANN_DEFINE_TYPE_INTRUSIVE macro.

Privacy: Struct generation runs entirely in your browser; the JSON never leaves your device, so you can safely use it for confidential protocols and internal data models.

Frequently Asked Questions

How do I use JSON → C++ Struct?
Step 2 — specify the root struct name (default RootObject ). Step 3 — the tool produces the corresponding struct definitions live; nested objects are split into their own structs and arrays uniformly use std::vector .
What can JSON → C++ Struct do?
Typical scenarios: C++ network service developers integrating HTTP JSON APIs; game engines (Unreal Engine, in-house engines) pulling configuration or protocol data from a server; embedded or IoT devices parsing JSON commands from the…
Is my data private when I use JSON → C++ Struct?
Privacy: Struct generation runs entirely in your browser; the JSON never leaves your device, so you can safely use it for confidential protocols and internal data models. Privacy: Struct generation runs entirely in your browser; the JSON never leaves your device, so you can safely use it for confidential protocols…
What technical details should I know about JSON → C++ Struct?
Null or mixed types are represented with auto (consider replacing with std::optional or std::variant ). Struct names are PascalCased.