libfuzzer

Installation
SKILL.md

libFuzzer

libFuzzer is an in-process, coverage-guided fuzzer that is part of the LLVM project. It's the recommended starting point for fuzzing C/C++ projects due to its simplicity and integration with the LLVM toolchain. While libFuzzer has been in maintenance-only mode since late 2022, it is easier to install and use than its alternatives, has wide support, and will be maintained for the foreseeable future.

When to Use

Fuzzer Best For Complexity
libFuzzer Quick setup, single-project fuzzing Low
AFL++ Multi-core fuzzing, diverse mutations Medium
LibAFL Custom fuzzers, research projects High
Honggfuzz Hardware-based coverage Medium

Choose libFuzzer when:

  • You need a simple, quick setup for C/C++ code
  • Project uses Clang for compilation
  • Single-core fuzzing is sufficient initially
  • Transitioning to AFL++ later is an option (harnesses are compatible)
Installs
3.0K
GitHub Stars
5.7K
First Seen
Jan 19, 2026
libfuzzer — trailofbits/skills