🔐

SSL Checker

Last updated:

Last updated:

Check SSL certificate information for any domain. View TLS version info, certificate details, and security recommendations. Educational tool for understanding SSL/TLS.

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⚠
Browser Limitations Notice
Due to browser security restrictions, this tool provides educational information about SSL/TLS and simulates certificate checks based on what can be detected client-side. For comprehensive SSL testing, use server-side tools like SSL Labs' SSL Test or OpenSSL commands.
🔒 HTTPS Status
Enter a domain
Check if the site supports HTTPS
🔑 TLS Version
-
Transport Layer Security version
📝 Certificate
-
Certificate validity status
🔭 HSTS
-
HTTP Strict Transport Security
📄 Certificate Details (Simulated)
Subject -
Issuer -
Valid From -
Valid Until -
Serial Number -
Signature Algorithm SHA-256 with RSA
SSL 3.0
Deprecated
TLS 1.0
Deprecated
TLS 1.1
Legacy
TLS 1.2
Secure
TLS 1.3
Recommended
SSL/TLS Security Best Practices
  • Always use TLS 1.2 or higher - disable older versions
  • Enable HSTS (HTTP Strict Transport Security) to force HTTPS
  • Use certificates with at least 2048-bit RSA keys
  • Keep certificates renewed before expiration
  • Implement OCSP Stapling for better performance
  • Use strong cipher suites and disable weak ones
  • Enable certificate transparency monitoring
🛈 Important: This tool provides educational information about SSL/TLS based on browser capabilities and simulated data. For comprehensive SSL testing including detailed cipher suite analysis, vulnerability scanning, and complete certificate chain validation, use server-side tools like Qualys SSL Labs or test from a server environment.

What the SSL Checker Does and Why It Matters

The SSL Checker is an educational tool that explains how HTTPS and TLS work and shows an illustrative, simulated certificate report for a domain you enter. Because browsers do not let a web page perform a raw TLS handshake against another site, this tool does not fetch a real certificate; it generates a representative example so you can learn what fields such as issuer, validity dates, and TLS version mean.

It is useful for understanding what to look for in a certificate and why an expired or misconfigured one breaks HTTPS and scares away visitors. For an authoritative audit of a live site, you still need a server-side scanner such as Qualys SSL Labs — this page is a learning aid, not a substitute for one.

How to Use SSL Checker

  1. Enter a domain or hostname to use as the example subject.
  2. Click Check SSL to run the simulated check.
  3. Read the illustrative certificate details (issuer, validity window, TLS version).
  4. Use the explanations to learn what each field means and why it matters.
  5. Note the on-page disclaimer that the data is simulated, not live.
  6. For a real audit, run the domain through a server-side tool such as Qualys SSL Labs.

Supported Inputs and Limitations

Supported input

  • A domain name or hostname used as the example subject
  • Any value you want to explore the explanations with

What you get

  • An illustrative, simulated certificate report
  • Plain-language explanations of TLS version, validity, and HSTS
  • Pointers to authoritative server-side tools for real testing

Known limitations

  • The tool makes no network request and does not read any real certificate; the values shown are simulated.
  • Browser security restrictions prevent client-side code from performing a genuine TLS handshake against a third-party host.
  • Do not use the output for compliance, security, or production decisions — verify with a server-side scanner.

Privacy and Security

Everything happens in your browser. The domain you type is used only to build the on-page example and is never sent to NovaTools or any external service, and nothing is stored after you leave. Because no real lookup is performed, this tool cannot expose anything about the domain you enter.

Frequently Asked Questions

Does this tool read my site’s real certificate?

No. Browsers do not allow a web page to perform a raw TLS handshake against another domain, so the certificate details shown here are a simulated example for learning. To inspect a live certificate, use a server-side scanner.

How do I properly test a live site’s SSL?

Use a server-side tool such as Qualys SSL Labs, or check the certificate directly in your browser by clicking the padlock in the address bar. Those sources read the actual certificate served by the host.

Is the domain I enter sent anywhere?

No. The value stays in your browser and is used only to populate the illustrative example. The tool makes no network request, so the domain is never transmitted or logged.

Related Tools

About SSL Checker

This educational tool helps you understand SSL/TLS certificates and HTTPS configuration. SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are cryptographic protocols that provide secure communication over a computer network. They are essential for protecting sensitive data transmitted between web browsers and servers.

How to Use

  1. Enter a domain name in the input field (e.g., "example.com").
  2. Click Check SSL to simulate an SSL check.
  3. Review the HTTPS status, TLS version, and certificate information.
  4. Check the Certificate Details section for simulated certificate data.
  5. Review the TLS Versions to understand which versions are secure.
  6. Follow the Security Best Practices recommendations.

Frequently Asked Questions

What is the difference between SSL and TLS?

SSL (Secure Sockets Layer) is the older protocol, with versions 1.0, 2.0, and 3.0. TLS (Transport Layer Security) is the newer, more secure successor with versions 1.0, 1.1, 1.2, and 1.3. TLS 1.3 is the current recommended version. The terms are often used interchangeably, but modern systems use TLS.

Why can't this tool perform full SSL checks?

Browsers restrict JavaScript from directly accessing low-level SSL certificate information for security reasons. Full SSL testing requires server-side tools that can establish raw TLS connections and analyze certificate chains, cipher suites, and protocol versions at the network level.

What is HSTS and why is it important?

HSTS (HTTP Strict Transport Security) is a security feature that tells browsers to always use HTTPS connections for a domain, preventing downgrade attacks and cookie hijacking. Once a browser receives an HSTS header, it will automatically upgrade HTTP requests to HTTPS for the specified duration.

How often should SSL certificates be renewed?

SSL certificates typically have validity periods ranging from 3 months to 2 years. Let's Encrypt certificates are valid for 90 days. It's recommended to automate renewal and monitor certificate expiration. Most CAs send renewal reminders 30, 14, and 7 days before expiration.

What makes a certificate trustworthy?

A certificate is trustworthy when it's issued by a trusted Certificate Authority (CA) that's included in major browser and operating system trust stores, hasn't expired, hasn't been revoked, is used on the correct domain, and has a valid certificate chain to a root CA.