Dev tools · alternatives · 2026

24 alternatives to Python JSON library in Rust, faster than ujson

Fast, correct Python JSON library supporting dataclasses, datetimes, and numpy - ijl/orjson

Python JSON library in Rust is a development tool that provides JSON parsing and serialization for Python applications using Rust for improved performance. It targets Python developers who need faster JSON handling… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Python JSON library in Rust, faster than ujson launched in 2018; newer entries below may have overtaken it.

1. 1AF
   Apache Fory Rust – 10-20x faster serialization than JSON/Protobuf▲67

   Serialization framework with some interesting numbers: 10-20x faster on nested objects than json/protobuf. Technical approach: compile-time codegen (no reflection), compact binary protocol with meta-packing, little-endian layout optimized for modern CPUs. Unique features that other fast serializers don't have: - Cross-language without IDL files (Rust ↔ Python/Java/Go) - Trait object serialization (Box) - Automatic circular reference handling - Schema evolution without coordination Happy to discuss design trade-offs. Benchmarks:…

   Oct 2025 · fory.apache.org · its alternatives →

2. 2
   A fast JSON library for Go▲119

   Fast JSON encoder/decoder compatible with encoding/json for Go - goccy/go-json

   2021 · github.com · its alternatives →

3. 3
   Streaming JSON in Rust▲7

   Terabytes of JSON, kilobytes of memory

   Jan 2026 · github.com · its alternatives →

4. 4
   Fast 2kB date library alternative to Moment.js with the same API▲122

   ⏰ Day.js 2kB immutable date-time library alternative to Moment.js with the same modern API - iamkun/dayjs

   2018 · github.com · its alternatives →

5. 5
   Cyjson – Fast and Efficent JSON Parser for Python▲10

   2015 · github.com · its alternatives →

6. 6
   Jason – A new JSON Library for Go▲106

   Easy-to-use JSON Library for Go. Contribute to antonholmquist/jason development by creating an account on GitHub.

   2014 · github.com · its alternatives →

7. 7
   fastjson - Fast JSON Parsing for Go▲20

   Fast JSON parser and validator for Go. No custom structs, no code generation, no reflection - valyala/fastjson

   2018 · github.com · its alternatives →

8. 8PA
   Python at the Speed of Rust▲68

   I’m sure many of you are familiar, but there’s a treacherous gap between finding (or building) a model that works in PyTorch, and getting that deployed into your application, especially in consumer-facing applications. I’ve been very interested in solving this problem with a great developer experience. Over time, I gradually realized that the highest-impact thing to have was a way to go from existing Python code to a self-contained native binary—in other words, a Python compiler. I was already pretty familiar with a successful attempt: when Apple introduced armv8 on the iPhone 5s, they…

   2025 · blog.fxn.ai · its alternatives →

9. 9
   JQL – A JSON Query Language CLI Tool Built with Rust▲25

   crates.io serves as a central registry for sharing crates, which are packages or libraries written in Rust that you can use to enhance your projects

   2020 · crates.io · its alternatives →

10. 10
    GPT-JSON – Structured and typehinted GPT responses in Python▲174

    Hey HN, I've been using GPT a lot lately in some side projects around data generation and benchmarking. During the course of prompt tuning I ended up with a pretty complicated request: the value that I was looking for, an explanation, a criticism, etc. JSON was the most natural output format for this but results would often be broken, have wrong types, or contain missing fields. There's been some positive movement in this space, like with jsonformer (https://github.com/1rgs/jsonformer) the other day. But nothing that was plug and play with GPT. This library consolidates…

    2023 · github.com · its alternatives →

11. 11
    A Fast, Malloc-Free C++14 Json Parser and Encoder▲98

    Meta programming utilities for C++14. Merged in matt-42/lithium - matt-42/iod

    2014 · github.com · its alternatives →

12. 12
    StaticJSON: fast, direct and static typed parsing of JSON with C++▲18

    Fast, direct and static typed parsing of JSON with C++ - netheril96/StaticJSON

    2016 · github.com · its alternatives →

13. 13
    Python library for embedding large graphs (Written in Rust)▲84

    Python library for embedding large graphs in 2D space, using force-directed layouts. - H4kor/graph-force

    2022 · github.com · its alternatives →

14. 14
    ut – Rust based CLI utilities for devs and IT▲170

    Hey HN, I find myself reaching for tools like it-tools.tech or other random sites every now and then during development or debugging. So, I built a toolkit with a sane and simple CLI interface for most of those tools. For the curious and lazy, at the moment, ut has tools for, - Encoding: base64 (encode, decode), url (encode, decode) - Hashing: md5, sha1, sha224, sha256, sha384, sha512 - Data Generation: uuid (v1, v3, v4, v5), token, lorem, random - Text Processing: case (lower, upper, camel, title, constant, header, sentence, snake), pretty-print, diff - Development Tools: calc, json…

    2025 · github.com · its alternatives →

15. 15
    Rust based eBook library for Python, with MIT license▲33

    fast, rust based epub library for python. Contribute to arc53/fast-ebook development by creating an account on GitHub.

    Apr 2026 · github.com · its alternatives →

16. 16
    ffjson: faster json serialization in Go▲83

    2014 · journal.paul.querna.org · its alternatives →

17. 17
    Robyn – A fast, extensible async Python web server with a Rust runtime▲103

    Robyn is a Super Fast Async Python Web Framework with a Rust runtime. - sparckles/Robyn

    2023 · github.com · its alternatives →

18. 18
    JSON Sharp▲73

    Tool for lazy developers to convert JSON to C# Objects

    2020 · jsontocsharpconverter.web.app · its alternatives →

19. 19
    Codon: A Compiler for High-Performance Pythonic Applications and DSLs [pdf]▲54

    2023 · regmedia.co.uk · its alternatives →

20. 20JA
    JsonTree, a 3.53kb JavaScript tool for generating html trees from JSON▲78

    a lightweight dependency free javascript micro-library for making collapsable trees with JSON

    2017 · maxleiter.github.io · its alternatives →

21. 21
    JSON-Threat-Protection Rust High-Performance Crate▲34

    A crate to protect against malicious JSON payloads. - ADD-SP/json-threat-protection.rs

    2024 · github.com · its alternatives →

22. 22
    Robyn – “Batman Inspired” Python Web Framework Built with Rust▲77

    Robyn is a high-performance async Python web framework powered by a Rust runtime. Build fast, scalable web applications with Python's simplicity and Rust's speed.

    2025 · robyn.tech · its alternatives →

23. 23
    High-Performance Wavelet Matrix for Python, Implemented in Rust▲93

    I built a Rust-powered Wavelet Matrix library for Python. There were surprisingly few practical Wavelet Matrix implementations available for Python, so I implemented one with a focus on performance, usability, and typed APIs. It supports fast rank/select, top-k, quantile, range queries, and even dynamic updates. Feedback welcome!

    Dec 2025 · pypi.org · its alternatives →

24. 24
    Speed Up Python with Rust via WebAssembly▲11

    speed up Python with Rust via WebAssembly - Oct 2020 - savarin/bridge

    2020 · github.com · its alternatives →

Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →