Jan 31, 2026 18:00:00

CertRadar allows you to search all certificates issued to a domain.

Public key certificates are issued by a trusted third party, a Certificate Authority (CA) , and are used to verify the legitimacy of websites. However, malicious attackers can sometimes obtain fraudulent certificates for legitimate domain names and use them for phishing sites or man-in-the-middle attacks, such as the Diginotar incident in 2011. To mitigate this risk, a tool is needed that can search all certificates issued to a domain. CertRadar is an online tool that allows you to easily search all certificates issued to a domain and identify domain risks.

SSL/TLS Security Tools - CertRadar
https://certradar.net/

About CertRadar
CertRadar

was revealed on Hacker News, a social news site. According to the author, it was built on Cloud Run using the Rust programming language. At the time of writing, six tools are available for free.

◆Cert Log Search
This tool searches for all certificates issued to a specified domain. Enter a domain name in 'Domain Name' and click the 'Search Certificates' button to search the Certificate Transparency (CT) log for certificates issued to that domain and display a list. Options include 'Include Subdomains' (include subdomains: default value checked) and 'Include Expired' (include expired certificates: default value not checked).

The information displayed is as follows:

・Matched Domain(s) : The domain name for which the certificate was issued
・Issuer : The certification authority that issued the certificate
・Not Before : The date and time when the certificate becomes valid
・Not After : Certificate expiration date and time
・crt.sh : Link to

crt.sh , which displays detailed certificate information

TLS Scanner
This is a tool for analyzing SSL-related issues. Enter a domain name in 'Hostname' and click the 'Analyze SSL/TLS' button to analyze and display the SSL/TLS settings for the specified domain.

The information displayed is as follows:

・Protocol Support : Supported TLS protocol versions
・Certificate Details : Detailed certificate information
HTTP Strict Transport Security (HSTS) : Learn more about HSTS

◆Header Search
This tool analyzes the settings of security-related HTTP headers such as HSTS, CSP, and X-Frame-Options. Enter a domain name in the 'Website URL' field and click the 'Analyze Headers' button to display the analysis results for the security headers of the specified domain.

When we analyzed gigazine.net, we received quite a few points of criticism, including the lack of HSTS.

◆Domain Health
This tool allows you to check the health of your DNS records and SSL in one view. Enter a domain name in 'Domain Name' and click the 'Check Domain Health' button to display the analysis results for the DNS records and SSL health of the specified domain.

The information displayed is as follows:

・CAA Analysis :

CAA record analysis results
・CNAME Chain : CNAME chain analysis results
・DNS Records : Analysis results of other DNS records

◆RDAP Lookup
This tool displays the results of a domain information query to

RDAP . Enter a domain name in 'Domain Name' and click the 'Query RDAP' button to display the RDAP response for the specified domain.

The information displayed is as follows:

・Registration Summary : Summary of information
・Nameservers : Nameserver information
・Raw RDAP Response : RDAP response JSON data

◆Multi-Domain Report
This tool outputs a comprehensive report for multiple domains. Enter up to 20 domain names separated by newlines in 'Enter domains' and click the 'Generate Report' button.

Generate a report summarizing various analysis results for each domain.

If you want to see more detailed information about the domain, click the 'Show Details' link.

Viewing details displays the following information about the domain:

・SSL/TLS
・Security Headers
・RDAP/WHOIS
DNS
・Issues : Issues pointed out

Summary
CertRadar is a useful online tool that can search all certificates issued to a domain, analyze SSL/TLS settings, security headers, DNS records, RDAP information, etc., and point out any problems. It is a very useful tool for website administrators, as it helps them understand the security status of their domains and identify potential risks.