Glaze is an extremely fast, header-only C++ library for serialization, deserialization, reflection, and RPC operations. It supports an extensive range of data formats including JSON, BEVE, BSON, CBOR, CSV, JSONB, MessagePack, TOML, YAML, and EETF, with each format available through separate headers to minimize compilation overhead. The library achieves remarkable performance metrics, with JSON roundtrip times of 1.01 seconds and write speeds of 1396 MB/s, significantly outperforming competing libraries like simdjson, yyjson, RapidJSON, and nlohmann/json according to the repository's benchmarks.
The core strength of Glaze lies in its compile-time reflection capabilities for C++23, which allow developers to serialize and deserialize aggregate-initializable structs without writing any metadata or macros. The library recently added support for C++26 P2996 reflection, unlocking advanced capabilities such as handling non-aggregate types with constructors and virtual functions, automatic enum serialization, support for unlimited struct members beyond the previous 128-member cap, and private member access. This standardized approach works across GCC 16+, Bloomberg clang-p2996, and other compliant compilers.
Glaze requires C++23 and is tested across Clang 18+, MSVC Visual Studio 2026, and GCC 13+ on Apple, Windows, and Linux platforms, including big-endian systems via QEMU emulation. The library compiles without exceptions or runtime type information when desired, making it suitable for constrained environments. It features JSON RFC 8259 compliance with UTF-8 validation, compile-time maps with perfect hashing, powerful wrapper systems for custom read/write behavior, JSON Schema generation, partial read/write support, and streaming I/O capabilities for handling large files with bounded memory. The library is currently expanding its networking capabilities with HTTP support including REST servers, clients, and WebSockets, though this functionality remains under active development with expected API changes.
