# altdns vs Cobalt Attack Surface Monitoring: side-by-side comparison (2026)

[altdns](https://cybersectools.com/tools/altdns) is a free [external attack surface management](https://cybersectools.com/categories/external-asm) solution. [Cobalt Attack Surface Monitoring](https://cybersectools.com/tools/cobalt-attack-surface-monitoring) is a commercial [external attack surface management](https://cybersectools.com/categories/external-asm) solution by [Cobalt](https://cybersectools.com/companies/cobalt). 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

| | altdns | Cobalt Attack Surface Monitoring |
|---|---|---|
| Pricing model | Free | Commercial |
| Category | External Attack Surface Management | External Attack Surface Management |
| Verified | No | No |
| Deployment type | On-Premises | Cloud |
| Company size fit | Startup, SMB, Mid-Market, Enterprise | SMB, Mid-Market, Enterprise |
| GitHub stars | 2,439 | – |
| Last commit | Jan 2025 | – |
| Company | – | Cobalt |
| Headquarters | – | – |

### Use cases and capabilities

| | altdns | Cobalt Attack Surface Monitoring |
|---|---|---|
| Reconnaissance | Yes | Yes |

### Core features

**altdns**

No features listed.

**Cobalt Attack Surface Monitoring**

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

### Integrations

**altdns**

No integrations listed.

**Cobalt Attack Surface Monitoring**

15 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.

- [altdns](https://cybersectools.com/tools/altdns) fits if you need to run it on your own servers, you are a startup, you need a free product and you want an open-source product.
- [Cobalt Attack Surface Monitoring](https://cybersectools.com/tools/cobalt-attack-surface-monitoring) fits if you want a cloud product.

## altdns vs Cobalt Attack Surface Monitoring FAQ

Common questions when comparing altdns vs Cobalt Attack Surface Monitoring for external attack surface management.

### What is the difference between altdns and Cobalt Attack Surface Monitoring?

**altdns**: A tool for generating permutations, alterations and mutations of subdomains and resolving them.

**Cobalt Attack Surface Monitoring**: Continuous external asset discovery and monitoring with daily domain scans. Built by Cobalt.

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

### Who makes altdns and Cobalt Attack Surface Monitoring?

**altdns** is open-source with 2,439 GitHub stars. **Cobalt Attack Surface Monitoring** is made by Cobalt. The vendor behind a product decides its roadmap, support, and longevity, so check each company's profile before you commit.

### Is altdns a good alternative to Cobalt Attack Surface Monitoring?

Often, yes. altdns and Cobalt Attack Surface Monitoring are both External Attack Surface Management products, and both cover Reconnaissance. Key differences: altdns is Free while Cobalt Attack Surface Monitoring is Commercial, altdns is open-source. Use the table above to see where features, deployment and company size fit differ.

## Related comparisons

- [altdns vs Censys Attack Surface Management](https://cybersectools.com/compare/altdns-vs-censys-attack-surface-management)
- [altdns vs Matos Automated Attack Surface Management](https://cybersectools.com/compare/altdns-vs-cloudmatos-automated-attack-surface-management)
- [altdns vs Palo Alto Networks Cortex Xpanse](https://cybersectools.com/compare/altdns-vs-palo-alto-networks-cortex-xpanse)
- [Cobalt Attack Surface Monitoring vs Censys Attack Surface Management](https://cybersectools.com/compare/censys-attack-surface-management-vs-cobalt-attack-surface-monitoring)
- [Cobalt Attack Surface Monitoring vs Matos Automated Attack Surface Management](https://cybersectools.com/compare/cloudmatos-automated-attack-surface-management-vs-cobalt-attack-surface-monitoring)
- [Cobalt Attack Surface Monitoring vs Palo Alto Networks Cortex Xpanse](https://cybersectools.com/compare/cobalt-attack-surface-monitoring-vs-palo-alto-networks-cortex-xpanse)

## Alternatives to each

- [See all altdns alternatives](https://cybersectools.com/alternatives/altdns)
- [See all Cobalt Attack Surface Monitoring alternatives](https://cybersectools.com/alternatives/cobalt-attack-surface-monitoring)

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Source: https://cybersectools.com/compare/altdns-vs-cobalt-attack-surface-monitoring

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

More on altdns and Cobalt Attack Surface Monitoring: 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