Fuzzing
Fuzzing tools test software by generating malformed inputs to discover memory safety bugs, parser crashes, and logic flaws before code reaches production.
Software in Fuzzing
10 toolsNo tools in this category match the selected filters.
| Tool | License | Platforms | Pricing |
|---|---|---|---|
| AFL++ Coverage-guided fuzzer with mutation engines, LLVM instrumentation plugins, and binary-only modes for finding memory safety bugs. | AGPL-3.0-or-later AND Apache-2.0 | Linux, macOS, FreeBSD, NetBSD, OpenBSD, Solaris, Android | Free / Commercial |
| Atheris Coverage-guided Python fuzzer from Google based on libFuzzer, designed for pure Python code and native CPython extensions. | Apache-2.0 | Linux, macOS | Open Source |
| boofuzz Python network protocol fuzzing framework for defining packet templates, tracking state machines, and discovering network crashes. | GPL-2.0-only | Linux, macOS, Windows | Open Source |
| FormatFuzzer Generates file-format fuzzers and parsers from 010 Editor binary templates. | GPL-3.0-only with public-domain/MIT exceptions | Linux, macOS | Open Source |
| Honggfuzz Multi-threaded, feedback-driven fuzzer using software and hardware coverage counters to uncover memory corruption defects. | Apache-2.0 | Linux, macOS, FreeBSD, NetBSD, Windows, Android | Open Source |
| Jazzer Coverage-guided in-process fuzzer for Java and the JVM based on libFuzzer, with built-in sanitizers for injection, path traversal, and SSRF bugs. | Apache-2.0 | Linux, macOS, Windows | Open Source |
| LibAFL Rust fuzzing library from the AFL++ team for building custom fuzzers from reusable components. | Apache-2.0 OR MIT | Linux, macOS, Windows, Android | Open Source |
| libFuzzer In-process, coverage-guided evolutionary fuzzing engine from LLVM for testing C and C++ libraries with AddressSanitizer. | Apache-2.0 WITH LLVM-exception | Linux, macOS, Windows | Open Source |
| Radamsa General-purpose mutational fuzzer that generates malformed test samples to test parser resilience and file format handlers. | MIT | Linux, macOS, FreeBSD, OpenBSD, Windows | Open Source |
| syzkaller Coverage-guided syscall fuzzer for Linux and other kernels, with declarative syscall descriptions. | Apache-2.0 | Linux | Open Source |
About Fuzzing
Fuzzing tools automatically test software by feeding it malformed, randomized, or edge-case inputs to discover crashes, memory leaks, and logic errors. The category divides into coverage-guided fuzzers and protocol fuzzers. Coverage-guided fuzzers like AFL++, libFuzzer, and honggfuzz track which code paths each input exercises, then mutate inputs that reach new code to maximize path coverage. They are effective at finding memory corruption bugs in parsers, decoders, and file format handlers. Protocol fuzzers like boofuzz target network protocols by sending malformed messages in a defined sequence, which exercises protocol state such as login steps. Fuzzing engines produce crash inputs that developers can reproduce and debug. When integrated into CI pipelines, fuzzing catches regressions in parsing code before releases. Modern fuzzing frameworks provide crash triage (grouping similar crashes), corpus management (storing inputs that maximize coverage), and sanitizers (detecting memory errors like buffer overflows and use-after-free during fuzzing runs). Most fuzzing tools are open source and integrate with compiler sanitizers like AddressSanitizer and UndefinedBehaviorSanitizer for deeper bug detection.
Covered Topics
In This Catalog
- This category lists 10 tools: 9 open source and 1 free / commercial.
- By platform, 10 run on Linux, 6 on Windows, and 9 on macOS.
- The most common license among the open-source tools is Apache-2.0 (4 tools).
Frequently Asked Questions
What is Fuzzing?→
Fuzzing tools test software by generating malformed inputs to discover memory safety bugs, parser crashes, and logic flaws before code reaches production.
What topics does the Fuzzing category cover?→
Coverage-Guided Fuzzing, Protocol & API Fuzzing, Mutation Engines, Crash Triage & Corpus Management, Compiler Sanitizer Integration
Which Fuzzing tools are open source?→
9 of the 10 tools in this category are open source: Atheris, boofuzz, FormatFuzzer, Honggfuzz, Jazzer, LibAFL, libFuzzer, Radamsa, and syzkaller.