SSL Certificate Checker
Inspect SSL/TLS trust layers, validation bounds, serial profiles, and intermediate certifications in real-time.
VALID SECURITY CERTIFICATE
Encryption keys are safe, active, and fully authorized.
Technical Cert Profile
EV Extended TrustSubject Alternative Names (SAN)
Cert Trust Path Chain
Lifespan Expiry Progress
Visualizing certificate timeline and renewal phases.
How It Works
Target Domain
Type in any host domain or IP.
Verify Trust
Retrieve the signature handshakes.
Audit Cert
Review trust chains and expiration calendars.
Frequently Asked Questions
What is TLS 1.3 encryption?
What is the difference between DV and EV certificates?
What is a Subject Alternative Name (SAN)?
Is That Padlock Actually Healthy?
What a certificate check covers
The browser padlock is a summary; the checker shows the details behind it:
| Check | Failure looks like |
|---|---|
| Validity dates | Expired cert — browsers block with a full-page warning |
| Hostname match | Cert for www.site.com used on api.site.com |
| Chain completeness | Works in Chrome, fails on Android apps and curl |
| Issuer | Self-signed = fine internally, alarming on a public site |
| Days remaining | The number to monitor — renewal failures are silent until they aren't |
The expiry that takes sites down
Certificate expiry is the most preventable outage on the internet — free certificates renew automatically until the automation silently breaks, and nobody notices for the remaining 60 days of validity. If you run anything public: check days-remaining monthly, and investigate any value that isn't resetting to ~90 (for Let's Encrypt) on schedule. The second classic: renewing the main domain but forgetting subdomains that carry their own certs.
Padlock ≠ trustworthy
HTTPS proves the connection is encrypted to whoever owns that domain — phishing sites have valid certificates too, since they're free. So the padlock answers “is my connection private?”, never “is this site honest?”. For the second question, check the domain's age and record in the WHOIS lookup. Connection errors that aren't certificate-related sort out via the HTTP status checker and DNS lookup.