TLS Server Testing Website

SSL Labs

SSL Labs is a Qualys website best known for SSL Server Test, a free online service that analyzes the SSL/TLS configuration, certificates, protocol support, cipher suites, and security posture of public HTTPS servers.

Official site

ssllabs.com is the main public website for SSL Labs.

Core tool

SSL Server Test performs a deep analysis of the SSL/TLS configuration of public web servers.

Operator

The SSL Labs site and contact page identify Qualys, Inc. as the company behind the service.

SSL Labs provides public SSL/TLS server testing and configuration analysis for HTTPS services.View logo asset on SSL Labs

What SSL Labs is

SSL Labs official site is a Qualys website for SSL/TLS research and testing. Its best-known tool, SSL Server Test, lets users submit a public hostname and receive a detailed report about the HTTPS server's certificate chain, protocol support, cipher suites, key exchange, vulnerabilities, and overall configuration grade.

SSL Server Test

SSL Server Test is designed for public internet servers. The official test page describes it as a free service that performs a deep analysis of any SSL web server on the public internet. Administrators commonly use it after changing certificates, enabling HTTPS, updating TLS settings, or troubleshooting browser and compliance issues.

What the report checks

A report can cover certificate trust, hostname matching, chain completeness, supported TLS versions, cipher strength, forward secrecy, HTTP Strict Transport Security, known protocol weaknesses, and other configuration details. The grade is useful, but the supporting notes are often more important than the letter itself.

Configuration guidance

SSL Labs is useful because TLS errors can be subtle. A server may work in modern browsers but still support outdated protocols, weak ciphers, incomplete chains, or compatibility choices that increase risk. The report helps administrators see which settings are strong, which are obsolete, and which need careful migration.

Privacy and scan visibility

The SSL Server Test page says submitted information is used to provide the service and includes an option not to show results on public boards. Even so, users should be thoughtful when testing systems that are not theirs. Public scanning services are best used for assets a user owns, manages, or has permission to assess.

Who uses SSL Labs

SSL Labs is used by system administrators, web developers, security engineers, compliance teams, certificate managers, hosting providers, auditors, and support staff. It is especially handy when a non-specialist needs a readable explanation of why an HTTPS setup is strong, weak, broken, or unexpectedly incompatible.

Limits and interpretation

A good SSL Labs grade does not prove an entire website is secure. It mainly evaluates the transport security configuration of a public HTTPS endpoint. Application vulnerabilities, authentication design, server-side code, account security, logging, and operational controls still require separate review.

Why it matters

HTTPS is now expected, but correct TLS configuration still affects privacy, compatibility, trust, and resilience against downgrade or interception risks. SSL Labs matters because it makes those technical settings visible and easier to improve, turning a complicated protocol stack into an actionable report.

WHOIS domain data

Data pulled: May 23, 2026View current WHOIS record

Domain: ssllabs.com
IP address: 69.67.183.100
Registrar: MarkMonitor Inc.
WHOIS server: whois.markmonitor.com
Referral URL: http://www.markmonitor.com
Created: January 1, 2009
Updated: December 1, 2025
Expires: January 1, 2028
Nameservers: tara.ns.cloudflare.com (108.162.192.225); seth.ns.cloudflare.com (173.245.59.142)
Domain status: clientDeleteProhibited https://icann.org/epp#clientDeleteProhibited; clientTransferProhibited https://icann.org/epp#clientTransferProhibited; clientUpdateProhibited https://icann.org/epp#clientUpdateProhibited
Contact privacy: Registrant organization is listed as Qualys, Inc.; contact email is provided through MarkMonitor's request form.

Key concepts

TLS configurationthe protocols, cipher suites, certificates, and server settings used to secure HTTPS connections.
Certificate chainthe sequence of certificates that links a site certificate to a trusted root authority.
Forward secrecya property that limits damage if a server's private key is compromised later.
Transport security gradea summarized signal that should be read alongside the detailed findings.

Website features

Run SSL Server Test against a public hostname.
Inspect certificate chain, hostname matching, trust, expiration, and protocol support.
Review TLS version, cipher suite, key exchange, forward secrecy, and vulnerability findings.
Use report details to guide HTTPS configuration improvements and regression checks.

Common misconceptions

An A or A+ grade does not mean the website's application code is secure.
A lower grade may reflect compatibility tradeoffs, old client support, or configuration debt rather than active compromise.
SSL Labs evaluates public endpoints; private services and internal routing may behave differently.
Retesting after certificate or server changes is important because TLS settings can regress during migrations.

Open questions

How should TLS testing tools balance strict security guidance with real-world compatibility requirements?
What report format best helps non-specialists fix TLS issues without misunderstanding the grade?
How will post-quantum cryptography change public TLS testing and grading systems?
Can automated remediation reduce weak TLS settings without causing outages for legacy clients?