# leibnitz27/cfr

This is the public repository for the CFR Java decompiler

Repository: https://github.com/leibnitz27/cfr
Canonical: https://ross.abutalabs.com/products/cfr
Homepage: https://www.benf.org/other/cfr
Language: Java
License: MIT
License Family: permissive
Last push: 2026-06-04T04:54:33+00:00

## Health v2 (maintenance only)
Score: 61/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 85, release rhythm 8, longevity 100
- inputs: {"age_days": 4496, "days_push": 90, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2675, forks 329 (observed 2026-08-28T04:07:09.747788+00:00)

## What it is
CFR (Class File Reader) is a Java decompiler written entirely in Java 6 that can decompile modern Java bytecode, including features from Java 9 through 14+, and even class files from other JVM languages. It can be used as a command-line tool on individual classes or entire jars, and also exposes an API since version 0.135.

## Use cases
- decompile a java class file back to source
- decompile an entire jar to java source code
- recover source code from compiled java bytecode
- decompile modern java features like switch expressions and pattern matching
- decompile kotlin or scala class files to java
- analyze obfuscated or third-party java bytecode
- use a java decompiler as a library via API

## When to choose
- you need to decompile bytecode from recent Java versions (9-14+) while running on an old JVM
- you want a dependency-free, standalone jar decompiler
- you need to decompile whole jars with output to a directory
- you want a decompiler usable both as CLI and as an embedded API

## When to avoid
- you need to decompile non-JVM languages like C or .NET assemblies
- you need a GUI-based decompiler experience
- you require line-number-perfect output for debugger use without caveats

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: parser, reverse-engineering, developer-tools
- domain: developer-tools, reverse-engineering
- platform: jvm, cli, cross-platform
- tags: java-decompiler, class-file-reader, bytecode-analysis, jar-decompilation, jvm

## Member repositories
- leibnitz27/cfr (main) score 61

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:09.747788+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 2026-08-30T02:18:02.647551+00:00, confidence not recorded.
  - readme: https://github.com/leibnitz27/cfr (fetched 2026-08-28T04:07:09.747788+00:00, sha f631304f5600)
  - homepage: https://www.benf.org/other/cfr (fetched 2026-08-29T10:00:32.333463+00:00, sha fe07304ac0b6)
  - site_page: https://www.benf.org/other/cfr/java9observations.html (fetched 2026-08-29T10:00:32.337323+00:00, sha 54f744cae7d1)
  - site_page: https://www.benf.org/other/cfr/faq.html (fetched 2026-08-29T10:00:32.339313+00:00, sha 26337ed49e14)
- Data as of 2026-08-30T08:39:29.467469+00:00.