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Best Fuzz Testing Software in 2026

Fuzz testing software explores program behavior using generated or varied inputs, with the aim of surfacing faults. Compared on input generation methods, supported languages, and target types, these entries can be weighed against the software you need to test. Execution mode, coverage guidance, and crash triage offer further criteria for understanding each testing approach. CI/CD support may be relevant to your workflow, while free-plan availability and paid-from pricing add access and cost details. ClusterFuzz, Accessibility Test Framework for Android, and AFL++ are among the options shown, along with cargo-fuzz and Mayhem. Compare the listed capabilities with your testing needs.

  1. 1

    Jazzer

    Free plan Open source APILinuxMac+2

    Jazzer combines coverage-guided fuzzing with JUnit integration and security-focused sanitizers for JVM targets.

    8.8 Free plan Visit site
  2. 2

    AFL++

    by AFL++
    Free plan AndroidLinuxMac+2

    AFL++ offers multiple instrumentation modes and target types, with free use under AGPL terms. Consider its hardware demands, macOS limitations, and license obligations before choosing a workflow.

    7.7 Free plan Visit site
  3. 3

    boofuzz

    Free plan APILinuxSelf-hosted+1

    boofuzz offers a broad set of communication options and a workflow for recording and responding to failures.

    7.6 Free plan Visit site
  4. 4

    ClusterFuzz

    Free plan LinuxMacSelf-hosted+2

    ClusterFuzz covers crash discovery through fix verification, with automation for testcase handling and bug workflows.

    7.5 Open source Visit site
  5. 5

    EvoMaster

    Free plan APILinuxMac+2

    EvoMaster provides free fuzz-based test generation across several API types and programming languages.

    7.5 Free plan Visit site
  6. 6

    cargo-fuzz

    Free plan LinuxMacWindows

    cargo-fuzz provides Rust projects with commands for fuzz-target setup, execution, input minimization, and coverage. Check the compiler and platform requirements before using it.

    7.4 Open source Visit site
  7. 7

    EvoMaster

    Free plan APILinuxMac+2

    EvoMaster offers free automated test generation across several API types, with both black-box and JVM-focused white-box modes.

    7.4 Free plan Visit site
  8. 8

    Fuzzinator

    Free plan LinuxMacWeb+1

    Fuzzinator automates fuzzing workflows, issue handling and scheduling, with configurable interfaces and optional tracker reporting.

    7.3 Open source Visit site
  9. 9

    Csmith

    Free plan LinuxWindows

    Choose Csmith when you need locally generated C programs for compiler comparisons or test-suite creation. Timely maintainer responses are not assured.

    7.2 Free plan Visit site
  10. 10

    Fuzzilli

    Free plan LinuxMacSelf-hosted

    Fuzzilli offers a configurable fuzzing setup with multiple target engines and coordination options. Building it requires a compatible instrumented engine and the specified toolchain.

    7.2 Open source Visit site
  11. 11

    Mayhem

    Free plan APILinuxMac+3

    Mayhem combines code testing, API testing and dynamic SBOM analysis, with a free API tier and a stated 30-day trial for paid plans.

    7.2 Pricing on request · 30-day trial Visit site
  12. 12

    Schemathesis

    Free plan LinuxMacSelf-hosted+1

    Schemathesis provides schema-based API testing with adaptive and stateful workflows, authentication options, and CI/CD integrations.

    7.0 Free plan Visit site
  13. 13

    Wfuzz

    Free plan LinuxMacSelf-hosted+1

    Choose Wfuzz if you need a free, locally run framework for generating inputs across HTTP requests and assessing web applications.

    6.9 Free plan Visit site
  14. 14

    FuzzForge

    Free plan Self-hostedWeb

    FuzzForge combines automated campaign execution with engineer takeover and several deployment models.

    6.8 Free plan Visit site
  15. 15

    Netzob

    Free plan LinuxWindows

    Choose Netzob for local protocol reverse engineering, traffic simulation, and fuzzing on Linux or Windows, especially when you need to derive models from traces.

    6.8 Free plan Visit site
  16. 16

    Onyx Launcher

    Free plan LinuxWindows

    Choose Onyx if you want a free launcher with instance management, Modrinth catalog access, Java runtime handling, and built-in diagnostics.

    6.8 Free plan Visit site
  17. 17

    OSS-Fuzz

    Free plan Web

    Eligible open-source projects should consider OSS-Fuzz for distributed fuzzing and private bug alerts at no charge.

    6.6 Free plan Visit site
  18. 18

    Black Duck Coverity

    Paid LinuxMacSelf-hosted+2

    Coverity pairs broad language and framework coverage with IDE, source-control, and CI integrations. Teams need to request a quote, and the facts list no free plan.

    6.0 Pricing on request Visit site
  19. 19

    RESTler

    Free plan LinuxMacWindows
    5.8 Free plan Visit site
  20. 20

    Fuzzowski

    Free plan
    5.6 Free plan Visit site
  21. 21

    Metalware

    Paid APILinuxSelf-hosted+1

    Metalware pairs emulated firmware execution with fuzzing and defect analysis, then provides debugging integrations and CI workflows.

    5.3 Pricing on request Visit site
  22. 22

    Fuzzware

    Paid Linux

    Fuzzware combines hardware-free firmware rehosting with automated, repeatable fuzzing and detailed reporting.

    4.9 Pricing on request Visit site
  23. 23

    beSTORM

    Paid LinuxWindows
    4.8 Pricing on request Visit site
  24. 24

    Honggfuzz

    Paid AndroidLinuxMac+1

    Honggfuzz provides mutation fuzzing with coverage guidance and crash triage across several target types.

    4.7 Open source Visit site
  25. 25

    syzkaller

    Paid LinuxMacWindows

    syzkaller provides generation, mutation, coverage guidance, and crash triage for kernel and syscall-interface fuzzing.

    4.1 Open source Visit site

#1Places #1, #2, #3, #4, #5 on this list can be bought by the makers of the software on it. See the price

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