# FYEO Custom Fuzz Testing vs RunSybil: side-by-side comparison (2026)

[FYEO Custom Fuzz Testing](https://cybersectools.com/tools/fyeo-custom-fuzz-testing) is a commercial [smart-contract scanning & dev security](https://cybersectools.com/categories/smart-contract-scanning) solution by [FYEO](https://cybersectools.com/companies/fyeo). [RunSybil](https://cybersectools.com/tools/runsybil) is a commercial [penetration testing](https://cybersectools.com/categories/pentesting-tools) solution by [RunSybil](https://cybersectools.com/companies/runsybil). Features, integrations, deployment and the company behind each one, side by side.

## Side-by-side comparison

| | FYEO Custom Fuzz Testing | RunSybil |
|---|---|---|
| Pricing model | Commercial | Commercial |
| Category | Smart-Contract Scanning & Dev Security | Penetration Testing |
| Verified | No | No |
| Deployment type | Hybrid | Cloud |
| Company size fit | Mid-Market, Enterprise | SMB, Mid-Market, Enterprise |
| Company | FYEO | RunSybil |
| Headquarters | – | – |

### Use cases and capabilities

| | FYEO Custom Fuzz Testing | RunSybil |
|---|---|---|
| Fuzzing | Yes | – |
| CI/CD | Yes | – |
| AI Pentesting | – | Yes |
| Attack Paths | – | Yes |
| Continuous Testing | – | Yes |
| Vulnerability Prioritization | – | Yes |
| Reconnaissance | – | Yes |
| DAST | – | Yes |
| Red Team | – | Yes |
| Security Scanning | – | Yes |
| Vulnerability | – | Yes |
| Cloud Native | – | Yes |

### Core features

**FYEO Custom Fuzz Testing**

8 features listed. Sign in on the page to see them.

**RunSybil**

10 features listed. Sign in on the page to see them.

## Which one fits you

Based on what each listing shows: deployment, company size, price and open source.

- [FYEO Custom Fuzz Testing](https://cybersectools.com/tools/fyeo-custom-fuzz-testing) fits if you need both cloud and on-premises options.
- [RunSybil](https://cybersectools.com/tools/runsybil) fits if you want a cloud product and you are a small business.

## FYEO Custom Fuzz Testing vs RunSybil FAQ

Common questions when comparing FYEO Custom Fuzz Testing vs RunSybil for smart-contract scanning & dev security.

### What is the difference between FYEO Custom Fuzz Testing and RunSybil?

**FYEO Custom Fuzz Testing**: Custom blockchain fuzz testing service with bespoke harnesses & CI integration. Built by FYEO.

**RunSybil**: AI-driven continuous attack surface assessment and validation platform. Built by RunSybil.

The table above shows where their features, integrations, deployment and company size fit differ.

### Who makes FYEO Custom Fuzz Testing and RunSybil?

**FYEO Custom Fuzz Testing** is made by FYEO. **RunSybil** is made by RunSybil. The vendor behind a product decides its roadmap, support, and longevity, so check each company's profile before you commit.

### Is FYEO Custom Fuzz Testing a good alternative to RunSybil?

In part. FYEO Custom Fuzz Testing and RunSybil are not in the same category on CybersecTools. Use the table above to see where features, deployment and company size fit differ.

## Related comparisons

- [FYEO Custom Fuzz Testing vs Olympix Enterprise-Grade Security Tools](https://cybersectools.com/compare/fyeo-custom-fuzz-testing-vs-olympix-enterprise-grade-security-tools)
- [FYEO Custom Fuzz Testing vs Dedge Security W3SPM](https://cybersectools.com/compare/dedge-security-w3spm-vs-fyeo-custom-fuzz-testing)
- [FYEO Custom Fuzz Testing vs CredShields SolidityScan](https://cybersectools.com/compare/credshields-solidityscan-vs-fyeo-custom-fuzz-testing)
- [RunSybil vs Olympix Enterprise-Grade Security Tools](https://cybersectools.com/compare/olympix-enterprise-grade-security-tools-vs-runsybil)
- [RunSybil vs Dedge Security W3SPM](https://cybersectools.com/compare/dedge-security-w3spm-vs-runsybil)
- [RunSybil vs CredShields SolidityScan](https://cybersectools.com/compare/credshields-solidityscan-vs-runsybil)

## Alternatives to each

- [See all FYEO Custom Fuzz Testing alternatives](https://cybersectools.com/alternatives/fyeo-custom-fuzz-testing)
- [See all RunSybil alternatives](https://cybersectools.com/alternatives/runsybil)

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Source: https://cybersectools.com/compare/fyeo-custom-fuzz-testing-vs-runsybil

For AI agents: each product above has its own Markdown page (add .md to its URL, for example https://cybersectools.com/tools/fyeo-custom-fuzz-testing.md). Every CybersecTools shortlist is listed at https://cybersectools.com/shortlists.md.

More on FYEO Custom Fuzz Testing and RunSybil: funding, momentum, hiring and news, plus the full product and company record, are available through the Mandos MCP Server (paid plans), which connects to AI assistants: https://mandos.io/mcp?utm_source=cybersectools.com&utm_medium=compare-md