Relevant Web Pages
What's the go to JSON parser in 2024/2025? : r/cpp - Reddit
If performance doesn't matter then NLohman JSON has a ton of great features. Glaze is faster than simdjson and usually requires much less code ...
reddit.com
Replacing nlohmann::json with a much faster alternative · Issue #14710 · NixOS/nix - GitHub
You might be able to speed up the performance of parsing by using another library and then copying the C++ structure like glz::generic into ...
github.com
JSON parsing: simdjson vs. JSON for Modern C++ - Daniel Lemire's blog
Thus, roughly speaking, simdjson can parse, validate a JSON document and create a DOM tree, at a speed of about 2 GB/s. The easier-to-use “JSON ...
lemire.me
Tried to pull together a list of C++ JSON parsers to compare them · nlohmann json · Discussion #2309 - GitHub
The JSONTestSuite is interesting but has no C++ parsers (which is what I am interested in). But I do like the image of conformance. I was not aware of simdjson.
github.com
Comparison to Other Libraries - Boost
Comparison to nlohmann JSON · basic_json is a class template. · Too much customization. · Poor separation of concerns. · Limited allocator support. · No incremental ...
boost.org
Reflection-based JSON in C++ at Gigabytes per Second - Daniel Lemire's blog
Our benchmark showed that we are roughly 20× faster than nlohmann/json. This was achieved by combining the new reflection capabilities with some ...
lemire.me
Parsing JSON in C & C++: Singleton Tax | Ash's Blog
The nlohmann::json library is designed to be simple and easy to use, but it's not the most efficient or flexible. The installation guide and the ...
ashvardanian.com
Python faster than C++ in deserializing json. Why? Is the json library in Python 3 written in C/C++ or other low-level language? - Stack Overflow
After a few runs, I had the shock to see that C++ takes 0.01 seconds and Python 3 takes about 0.001 seconds, which is almost 10 times faster!
stackoverflow.com
Why I built a JSON parser from scratch in 2025 | by Varun Santhanam - Medium
The first stop was simdjson, a breathtakingly fast C++ parser built around SIMD instructions. It parses gigabytes per second. It's rigorously ...
medium.com
nlohmann/json: JSON for Modern C++ - GitHub
In languages such as Python, JSON feels like a first-class data type. We used all the operator magic of modern C++ to achieve the same feeling in your code.
github.com
stephenberry/json_performance: Performance profiling of JSON libraries - GitHub
simdjson and yyjson are great, but they experience major performance losses when the data is not in the expected sequence or any keys are missing.
github.com
Benchmarks
In this section we compare the performance of Boost.JSON against the other two important libraries of interest, RapidJSON which is known for its considerable ...
230.jsondocs.prtest.cppalliance.org
JSON for Classic C++ - Hacker News
Dunking on nlohmann for performance is pretty easy. I'm interested in what the value proposition is over one of rapidjson, glaze, or simdjson ...
news.ycombinator.com
New, fastest JSON library for C++20 : r/cpp - Reddit
I will caveat that simdjson is probably faster in lazy contexts, but glaze should be faster when reading and writing directly from C++ structs.
reddit.com
On-Demand JSON: A Better Way to Parse Documents?
It consists in a JSON parser prototype with a simdjson-compatible interface, and it can serve as a drop-in replacement for the simdjson parser. Hahn et al. [13] ...
authorea.com
Reflection-based JSON in C++ at Gigabytes per Second - Francisco Geiman Thiesen
Our benchmark showed that we are roughly 20× faster than nlohmann/json. This was achieved by combining the new reflection capabilities with some ...
chico.dev
A Better Way to Parse Documents? - Simdjson
The simdjson On Demand API offers a familiar, friendly DOM API and provides the performance of just-in-time parsing on top of the simdjson superior performance.
simdjson.org
What is the best C++ JSON library? - Quora
JSON is frequently used in (at least) two rather different situations, and I'd choose the library depending on the situation.
quora.com
json - simdjson c++ parser - how to extract number of array elements - Stack Overflow
The ondemand::array does not have a size method. You can (but should not!) use std::distance and the begin() and end() methods.
stackoverflow.com