crt.guru vs tko-subs: side-by-side comparison (2026)
crt.guru is a commercial external attack surface management solution by Crt.guru. tko-subs is a free external attack surface management solution. Features, integrations, deployment and the company behind each one, side by side.
External TLS cert monitoring with expiry alerts, vuln scanning & compliance reports.
A tool for detecting and taking over subdomains with dead DNS records
Side-by-side comparison
Feature
crt.guru
tko-subs
Pricing model
Commercial
Free
Category
External Attack Surface Management
External Attack Surface Management
Deployment and fit
Deployment type
Cloud
On-Premises
Company size fit
Startup, SMB, Mid-Market, Enterprise
Startup, SMB, Mid-Market, Enterprise
Open source
GitHub stars
–
766
Last commit
–
Jan 2021
Company
Company
Crt.guru
–
Use cases and capabilities
TLS
Yes
No
SSL
Yes
No
PCI DSS
Yes
No
NIST
Yes
No
Security Scanning
Yes
No
Alerting
Yes
No
Security Compliance Training
Yes
No
Security Reporting
Yes
No
Vulnerability
Yes
No
REST API
Yes
No
Security Research
No
Yes
Subdomain Enumeration
No
Yes
Core features
10 features listed
No features listed
Integrations
4 integrations listed
No integrations listed
Need help choosing?
See more solutions in this category, or build a security stack from your picks.
