Cfr Java Decompiler Online

But for quick debugging, reverse-engineering a single class, or learning how Java compiles certain constructs – .

Let’s say you lost the source for a utility class but still have the compiled StringHelper.class .

Are you trying to decompile a specific (e.g., Java 17 or 21)?

If the online tools are too limited, you can run CFR locally on your machine with a single command. This is safer and faster.

| Service | CFR Version | File Size Limit | Extra Features | |---------|-------------|----------------|----------------| | (mirror) | Latest (v0.152+) | ~10 MB | Shows line numbers, optional comments | | Decompiler.com (select CFR engine) | v0.152 | 25 MB | Compare with Fernflower/JD-Core | | CodeJava.net CFR tool | v0.151 | 5 MB | Lightweight, fast |