CFR
CFR is a Java decompiler that turns Java class files into Java source.
What CFR is
CFR is a Java decompiler that turns Java class files into Java source. It can process individual named class files, classes on a classpath, or an entire JAR supplied by path. Its command-line tool can place decompiled files in a chosen directory with `--outputdir`, and command-line options or an options file can adjust the decompilation. The maker says CFR handles modern Java features, including much of Java 9, 12, and 14, and can attempt to decompile class files from other JVM languages. Those files are rendered as Java, not their original language. CFR is written in Java 6 and is said to work wherever Java 6 runs. It is available as a downloadable JAR, through Maven, and from the GitHub repository; the FAQ states that an API is available as of version 0.135. The repository identifies the license as MIT. CFR is free, with no paid plans or usage limits stated. The maker notes that some inputs fall into edge cases and may produce poor results.
Good
- Processes individual classes, classpaths, and JARs.
- Supports many modern Java features, according to its maker.
- Offers command-line options and an options file.
- Available as a JAR, through Maven, and on GitHub.
Watch out
- Other JVM language files are output as Java.
- Edge cases may produce poor results.
- Does not decompile native code.
Who it suits
CFR suits developers who need Java source from class files or JARs, including class files from other JVM languages. It may also suit projects that need command-line or API access to decompilation.
Verdict
CFR provides free bytecode decompilation with several ways to supply files and configure output. Be aware that non-Java JVM inputs become Java, and some cases may yield poor results.
Plans and prices
From CFR's own pricing page, checked 8 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free | Free | No paid plans or usage limits stated |
The facts
Each one read from CFR's own pages, with the date it was checked.
What it does
- API
- The FAQ states that CFR has an API as of version 0.135.checked 8 Oct 2026
- Configuration
- Decompilation can be customized with command-line options or an options file.checked 8 Oct 2026
- Distribution
- CFR is available as a downloadable JAR, through Maven, and from the GitHub repository.checked 8 Oct 2026
- Java support
- The maker says CFR can decompile modern Java features, including much of Java 9, 12, and 14.checked 8 Oct 2026
- JVM languages
- CFR can also attempt to turn class files from other JVM languages back into Java.checked 8 Oct 2026
- Known limitation
- The maker says CFR has edge cases and may produce poor results for some inputs.checked 8 Oct 2026
- License
- The maker’s FAQ directs users to the project README for its license; the project repository identifies the license as MIT.checked 8 Oct 2026
- Output
- The command-line tool can emit decompiled files to a specified output directory using --outputdir.checked 8 Oct 2026
- Output language
- For class files from other JVM languages, CFR generates Java output rather than the original language.checked 8 Oct 2026
- Purpose
- CFR is a Java decompiler that converts Java class files back into Java source.checked 8 Oct 2026
- Runtime
- CFR is written in Java 6 and the maker says it will work anywhere Java 6 runs.checked 8 Oct 2026
- Support
- The maker invites users to email reports of problems and directs bug reports to the GitHub issue tracker.checked 8 Oct 2026
- Support limitation
- The maker asks users not to submit class files they do not own the copyright to.checked 8 Oct 2026
- Usage
- CFR can decompile named class files or classes on a classpath, and can process an entire JAR by providing its path.checked 8 Oct 2026
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