SSL Certificate Checker

A quick SSL certificate checker for domain owners and admins to verify expiry, issuer, and chain status without manual certificate inspection.

Tool coming soon!

We're working hard to get this tool ready for you.

Request Feature / Support

1,964+

Total Calculations Run

< 15ms

Browser Execution Speed

100%

Client-Side Privacy

4.9 / 5.0

User Satisfaction

AI Web Tool Generator

Build Your Own Custom Web Calculator in Seconds

Type what tool or calculator you need below. Our AI will build it instantly for your site.

About This Tool

The tool analyzes an SSL certificate for a given domain by performing a TLS handshake and extracting the certificate chain. It surfaces essential details such as expiry date, issuer, subject, and SANs.
Conceptually, it compares the NotBefore/NotAfter validity window to the current time, computes days remaining, and classifies the certificate as valid, expired, or expiring soon. It also reports chain completeness and supported TLS versions or cipher hints.
Who benefits: website owners, IT admins, hosting providers, and SEO analysts who need proactive renewal planning and to avoid HTTPS warnings. Unique value: real-time, no setup required, concise, standardized outputs suitable for automation and monitoring.
Core features include domain input, immediate certificate fetch, expiry and issuer details, SANs, chain status, and optional protocol information. Use cases include verifying a domain after transfer, during renewal, or before a migration, and integrating results into monitoring workflows.

Save your calculation history with a free account

How to Use

Provide inputs: enter the domain name (and optional port).
The tool connects to the domain on port 443 and retrieves the SSL certificate.
The tool analyzes expiry, issuer, SANs, and chain status.
Review outputs: status, expires, days_remaining, issuer, san_list, and chain_status.
If expiring soon, plan renewal before expiry.

Frequently Asked Questions

Find Quick Answers

What data is shown by the checker?

It displays expiry date, days remaining, issuer, subject, SANs, chain status, and basic protocol information. Outputs are designed for quick risk assessment and integration into monitoring systems.

How is expiry calculated?

Expiry is calculated from the certificate's NotAfter date using current UTC time. Days remaining = ceil((NotAfter - now)/86400). Expired if NotAfter is in the past.

What if the domain has no TLS on port 443?

The checker returns an unknown or error status with a machine-readable reason indicating that TLS could not be established for port 443.

Does this tool perform revocation checks?

No, it does not perform OCSP/CRL revocation checks by default. It focuses on certificate validity, chain completeness, and basic TLS parameters.

Need to run multiple calculations?

Create a free account today to unlock unlimited daily runs, access advanced parameters, save your history, and request custom features.

Related Tools

Other useful calculators and utilities you might like

Spotify to MP3 Converter

Convert Spotify tracks and playlists to MP3 format instantly with our free online converter.

Road Distance Calculator

Calculate the driving distance and travel time between two addresses with our free online road dista...

Age Calculator

Calculate your exact age in years, months, and days from any birth date to any target date.

Currency Converter

Convert currencies instantly with real-time exchange rates and historical data support.

Your Feedback Matters

Help Us to Improve