# simdjson/simdjson

Parsing gigabytes of JSON per second : used by Facebook/Meta Velox, the Node.js runtime, ClickHouse, WatermelonDB, Apache Doris, Milvus, StarRocks

Repository: https://github.com/simdjson/simdjson
Canonical: https://ross.abutalabs.com/products/simdjson
Homepage: https://simdjson.org
Language: C++
License: Apache-2.0
License Family: permissive
Topics: json, json-parser, simd, avx2, sse42, neon, aarch64, arm64, vs2019, cpp11, gcc-compiler, clang-cl, clang, c-plus-plus, x64, json-pointer, avx512, loongarch, loongarch64, risc-v
Last push: 2026-08-26T18:56:06+00:00

## Health v2 (maintenance only)
Score: 99/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 99, longevity 100
- inputs: {"age_days": 3086, "days_push": 7, "days_rel": 7, "gap_med": 5, "n_releases_24m": 42}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 24196, forks 1275 (observed 2026-08-28T04:11:35.766981+00:00)

## What it is
A C++ library that parses JSON at gigabytes-per-second speeds using SIMD instructions and microparallel algorithms, with runtime CPU-tailored parser selection. It provides full JSON and UTF-8 validation and is widely adopted in production systems like Node.js, ClickHouse, and Meta Velox.

## Use cases
- parse json as fast as possible in c++
- validate utf-8 at high throughput
- minify large json files quickly
- parse ndjson streams at gigabytes per second
- speed up json parsing in a database engine
- replace rapidjson with a faster parser

## When to choose
- you need maximum JSON parsing throughput in C++
- you process large JSON or NDJSON datasets
- you want strict validation with lossless parsing
- you need a battle-tested parser used by major projects

## When to avoid
- you need a JSON serializer/writer more than a parser
- you work in a language without simdjson bindings
- your JSON payloads are tiny and parsing speed is irrelevant
- you need DOM-style mutable JSON manipulation

## Facets
- artifact type: library
- maturity: stable
- function: parser, serialization, json, benchmarking
- domain: parsers, performance, developer-tools, databases
- platform: cpp, cross-platform, windows, wasm
- tags: simd, json-parser, high-performance, avx2, avx512, neon, utf8-validation, ndjson, linux, macos, gpu

## Member repositories
- simdjson/simdjson (main) score 99

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:35.766981+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T16:56:16.700225+00:00, confidence not recorded.
  - readme: https://github.com/simdjson/simdjson (fetched 2026-08-28T04:11:35.766981+00:00, sha 915140d54e0c)
  - homepage: https://simdjson.org (fetched 2026-08-29T07:53:40.788912+00:00, sha 44136fa355b3)
- Data as of 2026-08-30T08:39:29.467469+00:00.