What does the SSL checker actually test?

It opens a real TLS connection to the host you enter and reports five things: whether the certificate is installed, valid and trusted; whether the intermediate chain is complete; the expiry date and days remaining; the Subject Alternative Names the certificate covers; and the protocol versions and cipher suites the server negotiates, including any known-weak ones.

Why does my certificate show as not trusted when it works in my own browser?

Almost always a missing intermediate certificate. Your browser may already have the intermediate cached from another site, so it fills the gap silently, but a fresh client does not. The fix is to install the full chain (leaf + intermediates) on the server. The checker flags this because it validates the chain as a clean client would.

Does a valid certificate mean my server is secure?

No. A certificate proves identity and enables encryption, but the server can still negotiate obsolete protocols (TLS 1.0/1.1), weak ciphers, or be exposed to vulnerabilities like POODLE or ROBOT. Certificate validity and configuration security are two separate checks; this tool reports both.

How often should I check my SSL certificate?

Check after every certificate renewal or server change, and set an expiry reminder. With short-lived certificates (90 days or less) now standard, automated monitoring is more reliable than manual checks.

Can I check certificates on internal or private hostnames?

No. The tool connects from the public internet, so it can only test publicly reachable hostnames. For internal names, run the equivalent check locally with OpenSSL: openssl s_client -connect host:443 -servername host.

Terms of Use & Legal Notice

Last updated: 16 June 2026

These terms govern your use of the diagnostic tools and content at ssl.org (the “Service”), operated by GW SOLUTIONS Ltd. By using the Service you agree to these terms.

What this Service is for

ssl.org exists to help you find and fix incorrect SSL/TLS and server configuration on systems you own or operate. It is a diagnostic aid, not an attack tool. You may use it only to test infrastructure you control or are explicitly authorised to test — never to probe, attack, exploit or gain unauthorised access to anyone else’s systems.

1. The Service

The Service provides tools that connect to a host you specify and report on its SSL/TLS certificate, chain of trust, expiry, protocol and cipher support, known-vulnerability exposure and response headers. Its purpose is to help operators identify misconfigurations and security weaknesses on their own systems so they can correct them.

2. Acceptable use and authorised testing

You agree that you will:

use the Service only to test systems that you own or operate, or for which you have explicit, documented authorisation from the owner;
use the results solely to understand and fix configuration and security issues;
comply with all applicable laws, including laws on unauthorised access to computer systems.

You agree that you will not:

use the Service to attack, exploit, disrupt, gain unauthorised access to, or otherwise harm any system;
test or scan systems you do not own and are not authorised to test;
use the Service for any unlawful, fraudulent or malicious purpose, or to facilitate any of the above.

Testing systems without the owner’s authorisation may be illegal in your jurisdiction and is strictly prohibited. You are solely responsible for ensuring you have the right to test any host you submit. We may rate-limit, suspend or block any use we consider abusive, and may cooperate with the authorities where required by law.

3. How the tools operate

The tools are designed to be non-intrusive: they inspect what a host presents to an ordinary client (its certificate, the protocols and ciphers it negotiates, and its response headers) and detect indicators of known vulnerabilities. They are not designed to exploit, damage or alter the target. Diagnostic input you submit is used only to perform the requested check — see our Privacy & Cookie Policy.

4. No warranty

The Service and its results are provided “as is” and “as available”, without warranty of any kind, express or implied, including accuracy, completeness, fitness for a particular purpose or non-infringement. Results are informational and are not a certification, audit or guarantee that a system is secure. You use the Service and rely on its results at your own risk, and should verify findings independently.

5. Limitation of liability

To the fullest extent permitted by law, GW SOLUTIONS Ltd. shall not be liable for any direct, indirect, incidental, consequential or other damages arising from your use of, or inability to use, the Service, or from reliance on its results. Nothing in these terms excludes or limits liability that cannot be excluded or limited under applicable law.

6. No professional advice

The Service does not provide security, legal or other professional advice. For decisions that matter, consult a suitably qualified professional.

7. Intellectual property

The Service, its tools, content and design are owned by GW SOLUTIONS Ltd. or its licensors. You may use the Service for its intended purpose, but may not copy, scrape, resell or build a competing service from it without our permission.

8. Availability and changes

The Service is provided on a best-effort basis and may change, be limited or be unavailable at any time without notice. We may update these terms from time to time; the “Last updated” date above shows the latest version.

9. Governing law

These terms are governed by the laws of Bulgaria and applicable EU law. Disputes are subject to the competent courts of Bulgaria, without prejudice to any mandatory consumer protections in your country of residence.

10. Legal notice (operator)

ssl.org is operated by:

GW SOLUTIONS Ltd. (Дружество с ограничена отговорност / ООД)
Asen Zlatarov 16, 4000 Plovdiv, Bulgaria
Company registration (ЕИК): 201793517 · VAT: BG201793517

ssl.org is provided by GW SOLUTIONS Ltd. as part of its IBAN.com services. Our infrastructure is hosted on Google Cloud Platform (Google Ireland Limited / Google LLC). We take care to keep the information and tools on ssl.org accurate and current, but provide them without warranty (see Section 4). Where the Service links to, or reports on, third-party websites or systems, we have no control over their content or configuration and accept no responsibility for them.

11. Contact

Questions about these terms or this notice? Email contact [at] iban [dot] com or use our contact form.