Self-Signed Certificate Checker

Check if a certificate is self-signed or CA-issued

About Self-Signed Certificates

A self-signed certificate is a certificate where the issuer and subject are identical — the certificate signs itself rather than being signed by a trusted Certificate Authority (CA). Self-signed certificates are commonly used for internal testing, development environments, and private networks where a CA-issued certificate is not required. However, browsers and public clients do not trust self-signed certificates by default. Our Self-Signed Certificate Checker helps you quickly determine if a server is using a self-signed or CA-issued certificate.

How to Use

Enter the domain name of the server you want to check.
Optionally change the port number (default is 443).
Click Check to fetch and analyze the server's certificate.
Review the result to see whether the certificate is self-signed or CA-issued, along with issuer and subject details.

Use Cases

Development Environment Validation: Confirm that internal services are using self-signed certificates as expected.
Security Auditing: Identify production servers that may be incorrectly using self-signed certificates.
Network Discovery: Scan your internal network to classify servers by certificate type.
Testing & QA: Verify that test environments are isolated from production CA trust chains.

Frequently Asked Questions

A self-signed certificate is a TLS certificate where the issuer and subject are the same entity. Unlike CA-issued certificates, it is not signed by a trusted third party. Browsers will display a security warning when encountering a self-signed certificate.

Self-signed certificates are appropriate for internal development, testing environments, lab networks, and private services where the clients trust the certificate directly. For public-facing production services, always use a CA-issued certificate.

Self-signed certificates provide the same level of encryption as CA-issued certificates. However, they lack the trust chain that allows browsers to automatically verify authenticity. The security depends on how the certificate is distributed and trusted by clients.

Tips & Best Practices

•Never use self-signed certificates in production environments
•Use self-signed certificates only for development and testing
•Replace self-signed with Let's Encrypt certificates for free trusted certificates
•Check all public-facing servers periodically for accidental self-signed deployment

Technical Details

Analysis: Issuer/subject comparison, signature verification, trust chain validation
Types: Self-signed, public CA-issued, private CA-issued, intermediate CA-issued
Trust: Cross-references against browser trust stores
Output: Certificate type determination with use case recommendations