Free tool
DNS & lookupSSL Expiry Checker
Check how many days remain on a public site’s TLS certificate and get a clear renewal urgency status.
Looks up public internet data for the target you enter. We do not store results.
Free toolExpired certificates cause abrupt outages that look like total site failure. This free SSL expiry checker focuses on the clock: valid-from, valid-to, days remaining, and a simple urgency label so website owners, small businesses, and cybersecurity students renew before users notice. Pair it with the full SSL Certificate Checker when you also need SANs and fingerprints.
How to use the SSL Expiry Checker
- 1
Enter the public hostname you want to monitor.
- 2
Tap Check expiry to read days remaining and the not-after date.
- 3
Renew early when status shows warning or critical, then re-check after deployment.
Why expiry monitoring prevents embarrassing downtime
Teams that only notice certificates when browsers scream already lost trust. Security testing calendars and email security gateways both depend on timely renewal. Checking days remaining here takes seconds and trains IT students to treat certificates as operational assets, not one-time setup.
Expiry check example
Check github.com or example.com. You should see a positive days-remaining value and a Healthy or Plan renewal status depending on the leaf lifetime. If a lab host shows Expired, browsers will block it until you replace the certificate.
Guides and next steps
Privacy note
We open a short TLS connection to read certificate dates for the host you enter. We do not store results.
Frequently asked questions
Explore more
Related free tools
More DNS, SSL, HTTP, and network lookup tools for troubleshooting and lab checks.
SSL Certificate Checker
Free SSL certificate checker for website owners and cybersecurity students. Inspect issuer, SANs, validity dates, and fingerprints for any public HTTPS host.
Open toolSecurity Headers Checker
Free HTTP security headers checker for website owners and cybersecurity students. Score HSTS, CSP, X-Frame-Options, and other hardening headers on any public site.
Open toolHTTP Status Checker
Free HTTP status code checker for web developers and IT support. See live status codes, redirect chains, and final URLs for any public website.
Open toolDNS Lookup
Free online DNS lookup for CCNA students and network engineers. Check A, AAAA, MX, TXT, NS, CNAME, SOA, and CAA records for any public domain in seconds.
Open toolPort Checker
Free online port checker for CCNA students and network engineers. Test whether common TCP ports are open on a public host from the internet.
Open toolPassword Strength Checker
Free password strength checker for cybersecurity students and website owners. Estimate strength locally in your browser—nothing is uploaded.
Open toolReady to go beyond free tools?
Live mentor-led courses turn calculator practice into real networking and IT skill.