Fuzzowski

At a glance

• Editor score
  6.7 / 10
• Pricing
  Free plan
• Best for
  Stateful network-protocol campaigns
• Free plan
  Yes
• Paid from
  Free
• Input generation methods
  mutation
• Facts checked
  20 Sep 2026

• Where it wins

  • Typed packet modeling with stateful responses and session variables
  • TCP, UDP, SSL, raw modes, and built-in protocol fuzzers
  • Suspect review, restarters, monitors, and Python PoC generation

• Where it doesn't

  • Focused on network protocols and services rather than broad application testing
  • Local execution may not fit distributed campaign requirements
  • Python 3 is the listed language support

Our verdict on Fuzzowski

Fuzzowski is an open-source Python 3 network protocol fuzzing tool for security testers who need structured, stateful campaigns. It supports finite, non-random mutation campaigns and lets users define packets and requests with typed primitives, blocks, and injection points. Campaign targets can use TCP, UDP, or SSL connections, while built-in fuzzers cover services and protocols including IPP, LPD, BACnet, Modbus, DHCP, TFTP, Telnet CLI, Netconf, COPS, and raw requests. Its focus is network protocol behavior rather than general-purpose application fuzzing.

The standout capability is campaign control. Stateful responses and session variables help model exchanges where later requests depend on earlier responses. Monitors detect unusual target behavior and mark suspects, while restarter modules support recovery when a target disconnects. The console provides pause, review, and retest workflows for suspect cases, and crash cases can produce Python proof-of-concept scripts. Together, these features support a repeatable path from packet definition to suspicious-case investigation without limiting campaigns to a single built-in protocol.

Fuzzowski is free and open source, with local execution and Python 3 language support. That makes it a practical fit for teams that want to inspect or extend the tool and are comfortable defining protocol structures and managing campaigns themselves. Its finite campaign model is useful when controlled mutation matters, but it is less suited to teams seeking broad, random, distributed, or cloud-managed fuzzing. Choose Fuzzowski for stateful testing of network protocols and services, especially when typed packet modeling, suspect review, recovery modules, and generated proof-of-concept scripts are priorities. Choose another tool if your primary targets are outside network protocols or if you need a wider execution platform.

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Fuzzowski pricing

Fuzzowski fact sheet

Alternatives to Fuzzowski

• MayhemMayhem brings broad hybrid fuzz testing, triage, and regression coverage to CI workflows.9.4
• OSS-FuzzA cloud-based continuous fuzzing service for qualifying open-source projects.9.2
• ClusterFuzzA broad, self-managed fuzzing platform for continuous security and stability testing.8.9

See all Fuzzowski alternatives →

Featured on iTechGuides

Fuzzowski is listed in our Fuzz Testing Software directory. Add the badge to your site — it links back to this page.

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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

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Last updated 7 Oct 2026 · How we research and update