The Best Fuzz Testing Software in 2026
We researched fuzz testing software through official websites, including pricing pages, plan tables, and product documentation. Products are ranked on their core fuzzing capabilities, value for money, and verified features for uncovering crashes, vulnerabilities, and unexpected behavior.
Our top picks
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Top ranked
Mayhem#1 of 259.4/10Mayhem brings broad hybrid fuzz testing, triage, and regression coverage to CI workflows.
Pricing on request · 30-day trial
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Runner-up
OSS-Fuzz#2 of 259.2/10A cloud-based continuous fuzzing service for qualifying open-source projects.
Free plan
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Top-ranked free plan
AFL++#4 of 258.7/10A broad, free fuzzer for native code, binaries, libraries, and file-processing tools.
Free plan
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
The full ranking 25 tools, best first
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Best forTeams needing broad managed fuzz testing
Mayhem brings broad hybrid fuzz testing, triage, and regression coverage to CI workflows.
- Coverage guidance
- CI/CD support
- Crash triage
Pricing on request · 30-day trial Our Mayhem verdict → Visit MayhemFor vendors Sponsor this spot · #1 · $149/mo →9.4/10★★★★★Visit Mayhem -
Best forFree continuous fuzzing for open-source projects
A cloud-based continuous fuzzing service for qualifying open-source projects.
- Coverage guidance
- CI/CD support
- Crash triage
9.2/10★★★★★Visit OSS-Fuzz -
Best forOrganizations needing managed fuzzing infrastructure
A broad, self-managed fuzzing platform for continuous security and stability testing.
- Coverage guidance
- CI/CD support
- Crash triage
8.9/10★★★★☆Visit ClusterFuzz -
Best forGeneral-purpose native and binary fuzzing
A broad, free fuzzer for native code, binaries, libraries, and file-processing tools.
- Coverage guidance
- CI/CD support
- Crash triage
8.7/10★★★★☆Visit AFL++ -
Best forAPI teams testing REST, GraphQL, and RPC
A broad, free API testing tool for teams covering REST, GraphQL, and RPC.
8.5/10★★★★☆Visit EvoMaster -
Best forSecurity teams wanting AI-assisted broad workflows
An AI-assisted fuzzing platform spanning local, cloud, API, firmware, and embedded workflows.
- Crash triage
8.3/10★★★★☆Visit FuzzForge -
Best forJVM application and library fuzzing
A free, open-source JVM fuzzer with strong CI and build-tool integration.
- Coverage guidance
- CI/CD support
- Crash triage
8.2/10★★★★☆Visit Jazzer -
Best forOperating-system kernel fuzzing
A focused open-source choice for coverage-guided operating-system kernel fuzzing.
- Coverage guidance
- CI/CD support
- Crash triage
8.1/10★★★★☆Visit syzkaller -
Best forCommercial firmware security testing
A commercial platform for deep, hardware-independent firmware security analysis.
- Coverage guidance
- CI/CD support
- Crash triage
8.0/10★★★★☆Visit Metalware -
Best forBlack-box protocol and binary testing
A broad black-box fuzzer for protocol, binary, file, hardware, DLL, and API testing.
- Crash triage
7.9/10★★★★☆Visit Fortra -
Best forBroad local native and binary fuzzing
A broad local fuzzer for native code, binaries, APIs, and network servers.
- Coverage guidance
- Crash triage
7.8/10★★★★☆Visit Honggfuzz -
Best forJavaScript engine fuzzing
A focused open-source fuzzer for finding crashes and coverage in JavaScript engines.
- Coverage guidance
- CI/CD support
- Crash triage
7.7/10★★★★☆Visit Fuzzilli -
Best forSelf-hosted OpenAPI and GraphQL testing
A free, self-hosted API fuzzer for schema-driven Python testing.
7.6/10★★★★☆Visit Schemathesis -
Best forStateful REST API fuzzing from OpenAPI
A focused choice for dependency-aware REST API fuzzing and reproducible findings.
7.5/10★★★★☆Visit RESTler -
Best forSpecialized embedded-firmware fuzzing
A focused choice for rehosting and fuzzing embedded firmware without physical hardware.
- Coverage guidance
- CI/CD support
7.4/10★★★★☆Visit Fuzzware -
Best forProtocol reverse engineering and fuzzing
A free, open-source toolkit for modeling, simulating, and fuzzing proprietary protocols.
7.3/10★★★★☆Visit Netzob -
Best forOpen-source protocol-state fuzzing
A scriptable, free choice for engineers testing modeled network and serial protocols.
- Crash triage
7.2/10★★★★☆Visit boofuzz -
Best forRust developers building fuzz targets
A focused open-source CLI for building local Rust fuzzing workflows.
- Coverage guidance
- CI/CD support
- Crash triage
7.1/10★★★★☆Visit cargo-fuzz -
Best forCompiler differential testing
A focused, reproducible generator for finding differences across C and C++ compilers.
- CI/CD support
6.9/10★★★☆☆Visit Csmith -
Best forCustom local fuzzing orchestration
A local, configurable fuzzing framework for orchestrating targets, generators, and issue triage.
- Crash triage
6.8/10★★★☆☆Visit Fuzzinator -
Best forStateful network-protocol campaigns
A focused, free tool for finite stateful campaigns against network protocols.
- Crash triage
6.7/10★★★☆☆Visit Fuzzowski -
Best forHTTP request and parameter fuzzing
A free, flexible HTTP fuzzer for security testing across request elements.
6.5/10★★★☆☆Visit Wfuzz -
Best forStatic analysis alongside fuzzing programs
A broad static-analysis platform for teams running fuzzing programs alongside code scanning.
5.3/10★★★☆☆Visit Coverity -
Best forHTTP proxy infrastructure, not fuzz testing
A capable HTTP proxy toolkit, but a poor fit for fuzz testing.
3.5/10★★☆☆☆Visit YARP -
Best forMinecraft instance and mod management
A capable Minecraft instance manager, but not a fuzz-testing tool.
3.0/10★★☆☆☆Visit Onyx Launcher
No tools match those filters.
Compare at a glance
| # | Tool | Free plan | Paid from | Input generation methods | Target types | Crash triage | Score |
|---|---|---|---|---|---|---|---|
| 1 | Mayhem | hybrid | Linux binaries; Windows PE binaries; TCP/UDP applications; REST APIs; gRPC APIs; containers; automotive vECUs | Yes | 9.4 | ||
| 2 | OSS-Fuzz | Yes | Free | mutation | source-code fuzz targets; untrusted user or network inputs; complex input formats | Yes | 9.2 |
| 3 | ClusterFuzz | Free | mutation, generation, hybrid | binary formats, HTML, JavaScript, browser DOM, native programs | Yes | 8.9 | |
| 4 | AFL++ | Yes | Free | mutation | source-code targets, binary-only targets, file inputs, stdin inputs, Android native libraries, Win32 PE binaries | Yes | 8.7 |
| 5 | EvoMaster | Yes | Free | 8.5 | |||
| 6 | FuzzForge | Yes | generation | codebases, binaries, containers, APIs, GraphQL, protocols, firmware, embedded systems | Yes | 8.3 | |
| 7 | Jazzer | Yes | Free | mutation, generation | JVM applications, Java, Kotlin, Scala, Clojure, JNI/native libraries | Yes | 8.2 |
| 8 | syzkaller | Free | generation, mutation | operating-system kernels and syscall interfaces: FreeBSD, Fuchsia, gVisor, Linux, NetBSD, OpenBSD, Windows | Yes | 8.1 | |
| 9 | Metalware | generation and mutation, with symbolic input generation | ELF and raw .bin firmware; ARM Cortex-M, embedded peripherals, DMA, RTOS, and bare metal targets | Yes | 8.0 | ||
| 10 | beSTORM | generation | network protocols, file formats, hardware, DLLs, APIs, binary applications | Yes | 7.9 | ||
| 11 | Honggfuzz | Free | mutation | file inputs, standard input, APIs, binaries, network servers | Yes | 7.8 | |
| 12 | Fuzzilli | Free | mutation, generation, hybrid | JavaScript programs and JavaScript engines/interpreters | Yes | 7.7 | |
| 13 | Schemathesis | Yes | Free | 7.6 | |||
| 14 | RESTler | Yes | Free | 7.5 | |||
| 15 | Fuzzware | mutation | ARM Cortex-M firmware; Infineon AURIX TriCore firmware; MMIO and interrupt-driven embedded systems | 7.4 | |||
| 16 | Netzob | Yes | Free | mutation, generation | network protocols, structured files, text protocols, delimiter-based protocols, fixed-field protocols, variable-length/TLV protocols, IPC, drivers and devices | 7.3 | |
| 17 | boofuzz | Yes | Free | hybrid | network protocols, serial, Ethernet/IP, UDP broadcast, TCP, UDP, SSL, raw sockets | Yes | 7.2 |
| 18 | cargo-fuzz | Free | mutation, generation, hybrid | raw byte buffers, structured Rust data, libraries, APIs, compiler code, allocator operations | Yes | 7.1 | |
| 19 | Csmith | Yes | Free | generation | C programs; C++ programs; compilers | 6.9 | |
| 20 | Fuzzinator | Free | generation, mutation | stdin, command-line, files, HTTP/browser | Yes | 6.8 | |
| 21 | Fuzzowski | Yes | Free | mutation | Network protocols and services including TCP, UDP, SSL, IPP, LPD, BACnet, Modbus, DHCP, TFTP, Telnet CLI, Netconf, COPS, and raw requests | Yes | 6.7 |
| 22 | Wfuzz | Yes | Free | generation | HTTP URLs, paths, files, query parameters, POST data, cookies, headers, HTTP verbs, authentication | 6.5 | |
| 23 | Coverity Static Analysis | No | 5.3 | ||||
| 24 | YARP | Free | 3.5 | ||||
| 25 | Onyx Launcher | Yes | Free | 3.0 |
Head-to-head All 28 comparisons →
- Mayhem vs OSS-Fuzz
- Mayhem vs ClusterFuzz
- Mayhem vs AFL++
- Mayhem vs EvoMaster
- Mayhem vs FuzzForge
- Mayhem vs Jazzer
- Mayhem vs syzkaller
- OSS-Fuzz vs ClusterFuzz
- OSS-Fuzz vs AFL++
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How we rank fuzz testing software
Every tool on this page was researched by iTechGuides Editors from its official website — pricing pages, plan tables and product documentation. We rank on how well each one does this category's core job, what the free or entry plan includes, and where it falls short. Where we have enough verified facts, the score out of 10 is a rubric — job fit, value and how much we could verify — shown with its breakdown on every tool's page; a tool we have not verified enough to score yet shows its rank without a number. Scores are re-checked when a product changes its plans. Read the full editorial policy, or submit a tool we missed.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Last updated · How we research and update