# rrousselGit/freezed

Code generation for immutable classes that has a simple syntax/API without compromising on the features.

Repository: https://github.com/rrousselGit/freezed
Canonical: https://ross.abutalabs.com/products/freezed
Homepage: https://pub.dev/packages/freezed
Language: Dart
License Family: other
Topics: flutter, dart, union-types, code-generator, hacktoberfest
Last push: 2026-08-26T21:00:48+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 2432, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2192, forks 305 (observed 2026-08-28T04:06:24.966420+00:00)

## What it is
Freezed is a Dart/Flutter code generator that creates immutable data classes, tagged unions, JSON serialization, copyWith, and equality implementations from simple annotations. It uses build_runner/source_gen to eliminate hundreds of lines of boilerplate model code.

## Use cases
- generate immutable data classes in dart
- reduce boilerplate for flutter models
- implement copyWith and equality automatically
- create tagged union types with pattern matching
- add fromJson/toJson serialization to dart classes
- model sealed class-like unions in dart

## When to choose
- you write Flutter/Dart apps with many model classes
- you want union types and pattern matching in Dart
- you want JSON (de)serialization generated for your models

## When to avoid
- your project does not use Dart/Flutter
- you prefer hand-written mutable classes or another generator like _serializable alone
- you cannot adopt a build_runner code-generation workflow

## Facets
- artifact type: library
- maturity: active
- function: serialization, developer-tools
- domain: developer-tools, mobile-development, frontend
- platform: cross-platform
- tags: code-generation, immutable-classes, data-classes, union-types, build-runner, flutter, pattern-matching, copywith, mobile

## Member repositories
- rrousselGit/freezed (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:24.966420+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 2026-08-30T02:47:27.171800+00:00, confidence not recorded.
  - readme: https://github.com/rrousselGit/freezed (fetched 2026-08-28T04:06:24.966420+00:00, sha d9fc8d157476)
  - homepage: https://pub.dev/packages/freezed (fetched 2026-08-29T10:27:49.512587+00:00, sha 0c430812d703)
  - site_page: https://pub.dev/documentation/freezed_annotation/latest/freezed_annotation/Freezed-class.html (fetched 2026-08-29T10:27:49.528180+00:00, sha a5b1e6d01506)
  - site_page: https://pub.dev/packages/freezed/install (fetched 2026-08-29T10:27:49.525913+00:00, sha 58be15f92063)
  - site_page: https://pub.dev/documentation/freezed/latest (fetched 2026-08-29T10:27:49.530576+00:00, sha 5843fc7ac154)
  - site_page: https://pub.dev/packages/freezed/changelog (fetched 2026-08-29T10:27:49.522919+00:00, sha 896177bd51b5)
- Data as of 2026-08-30T08:39:29.467469+00:00.