Certificate Issuer Identifier

Identify the certificate authority that issued the SSL certificate

About Certificate Issuers

Every SSL/TLS certificate is issued by a Certificate Authority (CA) that verifies the domain owner's identity before signing the certificate. Knowing your certificate issuer helps you understand the trust chain, validation level, and renewal process. Our Certificate Issuer Identifier fetches a server's certificate and reveals the issuing CA, organization details, country of origin, and whether the certificate is self-signed or from a recognized authority.

How to Use

Enter the domain name whose SSL certificate issuer you want to identify.
Click Identify to fetch the certificate and extract issuer details.
Review the issuer name, organization, country, and known CA information.
Check if the certificate is self-signed or issued by a trusted CA.

Use Cases

CA Discovery: Quickly determine which CA issued a certificate for any domain on the internet.
Validation Checks: Verify that certificates are issued by trusted authorities rather than being self-signed.
Renewal Planning: Identify the CA to understand renewal policies, pricing, and support options.
Security Research: Investigate certificate issuance patterns and CA prevalence across the web.

Frequently Asked Questions

A Certificate Authority (CA) is a trusted organization that issues digital certificates used to verify the identity of websites. CAs validate domain ownership and organization details before signing certificates, creating the chain of trust that browsers rely on.

Browsers and operating systems maintain a list of trusted root CAs. If your certificate is issued by a CA in these trusted root stores, browsers will accept it. Our tool shows whether the CA is recognized and provides additional information about the issuer.

A self-signed certificate is one where the subject and issuer are the same entity. It is not signed by a trusted CA. Self-signed certificates are commonly used in development and internal networks but trigger browser warnings in production because they lack third-party validation.

An intermediate, in almost every case — the organisation in the issuer field is the authority that signed your specific certificate, which is usually not the root in your trust store. Root certificates sign intermediates directly and are held back deliberately so that compromising one does not compromise everything issued beneath it. When you ask whether a certificate is trusted, you are asking whether that intermediate chains to a root you hold.

Because authorities delegate. The commercial brand you bought from operates one or more intermediates and issues through one of them, so the certificate names the intermediate rather than the brand. The root may carry the brand name you recognise. This is deliberate security design rather than an inconsistency, and it is why removing a root from your trust store disables everything issued under it.

Yes, and it is normal. Large authorities operate multiple intermediates, sometimes for different products, regions or assurance levels, and a single organisation name may appear with different common names on each. That is why matching certificates by organisation alone is unreliable — the authority key identifier is what distinguishes a specific issuing certificate from its siblings.

No, and this is worth being clear about. The issuer identifies who signed the certificate; the subject alternative names identify which domains the certificate is valid for. Neither field is a statement about who owns or controls anything. The authority verified control of the names as part of issuance according to its policy, which is what gives the subject field its meaning.

Distinguishing a specific issuing certificate from others sharing an organisation name, and it lets you look that certificate up in the authority's published records. In practice it matters during incidents and audits — you can establish exactly which intermediate signed a given certificate and therefore which root trust anchor governs it, rather than inferring from a name.

What Identifies An Authority

Several attributes in a certificate name the authority that issued it, and they are not interchangeable. This page reads them and reports each one as the certificate states it.

1Read the organisation and common name from the issuer, which is how the issuing authority appears. This is what tells you a Let's Encrypt certificate from a commercial one, and it is the first thing to check when a site unexpectedly fails validation.
2Report the distinction between the immediate issuer and the root. A certificate is normally signed by an intermediate, not the root, so the issuer field names the intermediate while the authority you are thinking of is the root above it. Conflating the two is the source of most confusion about who issued what.
3Report the Authority Key Identifier and serial, which identify the specific issuing certificate rather than the organisation. That is what you need to correlate an issuer with a particular intermediate during an incident.

This page identifies the issuer from the certificate alone. Whether that issuer chains to a root your clients trust is a separate question, answered by the trust verification page.

Tips & Best Practices

•Identify certificate issuers to understand trust relationships
•Monitor certificate issuance patterns for security awareness
•Compare issuer information across certificates from different CAs
•Use issuer identification for certificate inventory management

Technical Details

Identification: Certificate issuer (CA) identification and analysis
Fields: Organization, organizational unit, common name, country
Trust: Issuer trust status and reputation
Output: Issuer details with trust and reputation information