SSL Certificate Checker & Expiry Inspector

Check SSL/TLS certificate details, validation status, key algorithms, and chain details directly from secure host handshakes.

The DwellixTools SSL Certificate Checker & Expiry Inspector allows developers, system administrators, and site owners to instantly query any server’s TLS handshake configuration. It returns a detailed breakdown of the certificate’s subject, issuer, expiration dates, cipher parameters, and cryptographic chain.

Our tool connects directly to the target host and port to perform a query-only TLS handshake, providing authoritative status updates without relying on cached data or third-party query aggregates.

Key Features

  • Authoritative Direct Handshake: Establishes a TLS socket connection directly to the server’s specified port to inspect active certificate properties in real-time.
  • Expiration Countdown: Displays a live countdown timer showing the remaining days, hours, and minutes before validity ends.
  • Certificate Chain Viewer: Visualizes the complete trust path from the Leaf (End Entity) certificate, through intermediate Certificate Authorities (CAs), up to the Root CA.
  • Subject Alternative Names (SAN): Extracts and indexes all alternative domains protected by the active certificate, featuring a built-in search and filter tool.
  • Cryptographic Details: Reports the signature algorithm, public key type, key bit size, serial number, and SHA-1/SHA-256 fingerprints.
  • Insecure Certificate Support: Handles and parses expired, not-yet-valid, or self-signed certificates without failing the handshake, allowing diagnostic inspection of misconfigured hosts.

How to Check an SSL Certificate

  1. Enter Hostname: In the input field, type the domain name or host IP you wish to check (e.g. google.com).
  2. Specify Port (Optional): Enter the port listening for TLS connections (defaults to 443 for HTTPS).
  3. Inspect Results: Click Check Certificate. The serverless backend will complete a TLS handshake and return the certificate parameters.
  4. Browse Workspaces: Click through the tabs (Overview, SAN Domains, Certificate Chain, Advanced JSON) to inspect different metadata fields or copy the raw certificate structure.

Frequently Asked Questions (FAQs)

What does “Self-Signed” mean?

A self-signed certificate is one that is signed by the same entity that it identifies, rather than a trusted Certificate Authority (CA) like Let’s Encrypt or DigiCert. While self-signed certificates encrypt traffic, browsers will display a security warning because there is no trusted third party verifying the identity of the server.

Does this tool store or log the certificates checked?

No. DwellixTools processes TLS handshakes serverlessly in real-time. Checked hosts, ports, and certificate outputs are not stored, logged, or cached on our servers.

Can I test hosts using custom ports?

Yes. The port input supports any valid port number from 1 to 65535 (for example, port 8443 or 4443 used in development environments).

Why does a certificate show as expired?

A certificate shows as expired if the current system date and time are past the certificate’s validity end date (validTo). To resolve this, the site administrator must renew the certificate and reload the web server configuration.