# michalmuskala/jason

A blazing fast JSON parser and generator in pure Elixir.

Repository: https://github.com/michalmuskala/jason
Canonical: https://ross.abutalabs.com/products/jason
Language: Elixir
License: NOASSERTION
License Family: other
Topics: elixir, json
Last push: 2026-05-05T14:34:16+00:00

## Health v2 (maintenance only)
Score: 59/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 80, release rhythm 8, longevity 100
- inputs: {"age_days": 3377, "days_push": 120, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1680, forks 178 (observed 2026-08-28T04:05:21.457319+00:00)

## What it is
Jason is a fast, standards-compliant JSON parser and generator written in pure Elixir. It is the default JSON codec for many Elixir ecosystem libraries such as Ecto, Phoenix, and Postgrex.

## Use cases
- encode elixir maps to
- parse  strings in elixir
- fast  serialization for phoenix apis
- codec for ecto and postgrex
- rfc 8259 compliant  handling

## When to choose
- you need a fast pure-elixir  library without native NIF dependencies
- you use Phoenix, Ecto, or Postgrex and want the ecosystem default
- standards compliance and extensive test coverage matter

## When to avoid
- you need maximum raw speed and are comfortable with C NIFs like jiffy
- you need non-standard  extensions or custom decoding options

## Facets
- artifact type: library
- maturity: stable
- function: serialization, parser
- domain: developer-tools, apis, web-development
- platform: elixir
- tags: encoder, decoder, pure-elixir, rfc-8259

## Member repositories
- michalmuskala/jason (main) score 59

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:21.457319+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 2026-08-30T03:41:28.478608+00:00, confidence not recorded.
  - readme: https://github.com/michalmuskala/jason (fetched 2026-08-28T04:05:21.457319+00:00, sha 7a1cd00a9767)
- Data as of 2026-08-30T08:39:29.467469+00:00.