Free CAA Records Checker
Validate CAA DNS records to control which Certificate Authorities can issue certificates for your domain. Prevents unauthorized cert issuance and domain hijacking.
- CAA record validation and analysis
- Certificate Authority authorization check
- Wildcard and subdomain CAA coverage

What you get for free
18 core security checks via this tool, passive scans, step-by-step remediation, security score on every result.
What Essential adds at $39/mo
+17 advanced checks, continuous monitoring, daily security score history, email alerts, GitHub SAST, board-ready PDFs, SOC 2 / ISO 27001 / PCI reports.
What this checker validates
- Presence and configuration of CAA records
- Authorized Certificate Authorities list
- Wildcard and subdomain CAA coverage
- CAA record syntax and policy compliance
- Certificate issuance policy validation
What are CAA Records?
CAA (Certificate Authority Authorization) records are DNS records that specify which Certificate Authorities (CAs) are authorized to issue SSL/TLS certificates for your domain. This helps prevent unauthorized certificate issuance and domain hijacking attacks.
How to configure CAA Records
- Basic CAA: 0 issue "letsencrypt.org" (allow Let's Encrypt)
- Restrictive CAA: 0 issue "digicert.com" (only DigiCert)
- Wildcard CAA: 0 issuewild "sectigo.com" (wildcard certs only from Sectigo)
- Report-only: 0 iodef "mailto:security@example.com" (report violations)
Benefits of CAA Records
- Prevents unauthorized certificate issuance by malicious CAs
- Reduces risk of domain hijacking and phishing attacks
- Provides audit trail for certificate issuance
- Enhances overall domain security posture
- Compliance with security best practices
Implementation examples
CAA records are added like any other DNS record, straight from your DNS provider's dashboard. Add these three at the root of your domain, replacing letsencrypt.org with whichever CA actually issues your certificates:
| Type | Name / Host | Value |
|---|---|---|
| CAA | @ | 0 issue "letsencrypt.org" |
| CAA | @ | 0 issuewild ";" |
| CAA | @ | 0 iodef "mailto:security@example.com" |
Some dashboards (Cloudflare, Route 53) split the value into separate flag, tag, and value fields instead of one string: flag is 0, the tag is issue, issuewild, or iodef, and the value is the CA domain or mailto address. The issuewild line with ";" blocks wildcard certificates entirely, so drop it if you use them.
Self-hosted DNS (BIND zone file)
example.com. IN CAA 0 issue "letsencrypt.org"
example.com. IN CAA 0 issuewild ";"
example.com. IN CAA 0 iodef "mailto:security@example.com"Tool-specific questions
Are CAA records mandatory?
What happens if I don't have CAA records?
Can I have multiple CAA records?
How do CAA records affect wildcard certificates?
Should I monitor CAA records regularly?
Built for the engineers who already have enough to fix.
Real-time results
Comprehensive checks
Step-by-step fixes
More free checks, for the rest of your surface.
Complete Security Scan
Pre-Pentest Security Scan
Security Compliance Checker
WAF Checker
Security Headers Test
TLS/SSL Security Checker
Frequently asked.
What is Barrion and how does it enhance website security?
How safe is Barrion to use for security testing?
What types of security issues does Barrion identify?
What specific security checks does Barrion perform?
What is Barrion's smart crawling?
How often does Barrion perform security scans?
Is Barrion suitable for security testing of all business sizes?
How does Barrion handle data security and privacy during security testing?
What if I'm not satisfied with Barrion's security testing service?
How does Barrion help with SOC 2, ISO 27001, NIS2, and other compliance frameworks?
Anything else? Email contact@barrion.io.