# Chaos Client vs crt.guru: side-by-side comparison (2026)

[Chaos Client](https://cybersectools.com/tools/chaos-client) is a free [external attack surface management](https://cybersectools.com/categories/external-asm) solution. [crt.guru](https://cybersectools.com/tools/crtguru) is a commercial [external attack surface management](https://cybersectools.com/categories/external-asm) solution by [Crt.guru](https://cybersectools.com/companies/crtguru). Features, integrations, deployment and the company behind each one, side by side.

Need the answer fast? [Best Attack Surface Management Solutions for Business](https://cybersectools.com/shortlists/best-attack-surface-solutions) picks Palo Alto Networks Cortex Xpanse, Microsoft Defender EASM, Mandiant Attack Surface Management and 4 more.

## Side-by-side comparison

| | Chaos Client | crt.guru |
|---|---|---|
| Pricing model | Free | Commercial |
| Category | External Attack Surface Management | External Attack Surface Management |
| Verified | No | No |
| Deployment type | Cloud | Cloud |
| Company size fit | Startup, SMB, Mid-Market, Enterprise | Startup, SMB, Mid-Market, Enterprise |
| GitHub stars | 763 | – |
| Last commit | Apr 2024 | – |
| Company | – | Crt.guru |
| Headquarters | – | – |

### Use cases and capabilities

| | Chaos Client | crt.guru |
|---|---|---|
| Reconnaissance | Yes | – |
| TLS | – | Yes |
| SSL | – | Yes |
| PCI DSS | – | Yes |
| NIST | – | Yes |
| Security Scanning | – | Yes |
| Alerting | – | Yes |
| Security Compliance Training | – | Yes |
| Security Reporting | – | Yes |
| Vulnerability | – | Yes |
| REST API | – | Yes |

### Core features

**Chaos Client**

No features listed.

**crt.guru**

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

### Integrations

**Chaos Client**

No integrations listed.

**crt.guru**

4 integrations 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.

- [Chaos Client](https://cybersectools.com/tools/chaos-client) fits if you need a free product and you want an open-source product.

## Chaos Client vs crt.guru FAQ

Common questions when comparing Chaos Client vs crt.guru for external attack surface management.

### What is the difference between Chaos Client and crt.guru?

**Chaos Client**: A Go client to communicate with Chaos DB API.

**crt.guru**: External TLS cert monitoring with expiry alerts, vuln scanning & compliance reports, built by Crt.guru.

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

### Who makes Chaos Client and crt.guru?

**Chaos Client** is open-source with 763 GitHub stars. **crt.guru** is made by Crt.guru. The vendor behind a product decides its roadmap, support, and longevity, so check each company's profile before you commit.

### Is Chaos Client a good alternative to crt.guru?

Often, yes. Chaos Client and crt.guru are both External Attack Surface Management products. Key differences: Chaos Client is Free while crt.guru is Commercial, Chaos Client is open-source. Use the table above to see where features, deployment and company size fit differ.

## Related comparisons

- [Chaos Client vs Attack Surface Scan](https://cybersectools.com/compare/attack-surface-scan-vs-chaos-client)
- [Chaos Client vs SurfaceDiff](https://cybersectools.com/compare/chaos-client-vs-surfacediff)
- [Chaos Client vs DDactic Attack Surface Discovery](https://cybersectools.com/compare/chaos-client-vs-ddactic-attack-surface-discovery)
- [crt.guru vs Attack Surface Scan](https://cybersectools.com/compare/attack-surface-scan-vs-crtguru)
- [crt.guru vs SurfaceDiff](https://cybersectools.com/compare/crtguru-vs-surfacediff)
- [crt.guru vs DDactic Attack Surface Discovery](https://cybersectools.com/compare/crtguru-vs-ddactic-attack-surface-discovery)

## Alternatives to each

- [See all Chaos Client alternatives](https://cybersectools.com/alternatives/chaos-client)
- [See all crt.guru alternatives](https://cybersectools.com/alternatives/crtguru)

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Source: https://cybersectools.com/compare/chaos-client-vs-crtguru

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

More on Chaos Client and crt.guru: 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