SSL Certificate Checker
Inspect SSL/TLS certificates. Check issuer, validity dates, subject alternative names, and certificate chain.
Certificate Details
| Subject | |
| Issuer | |
| Valid from | |
| Valid to | |
| Algorithm | |
| Serial | |
| Protocol |
Subject Alternative Names
Certificate Chain
Other DNS Tools
DNS Lookup
Query DNS records for any domain. Check A, AAAA, MX, CNAME, TXT, NS, SOA, SRV, CAA, and PTR records.
DNS Propagation Checker
Check if DNS changes have propagated across global DNS servers. Verify updates from Google, Cloudflare, OpenDNS, and more.
SPF / DKIM / DMARC
Generate SPF and DMARC records and validate SPF, DKIM, and DMARC. Improve email deliverability and protect against spoofing.
WHOIS Lookup
Look up domain registration information. Find registrar, creation date, expiry date, nameservers, and contact details.
Blacklist Check
Check if an IP address or domain is listed on DNS-based blacklists (DNSBL). Test against Spamhaus, Barracuda, SpamCop, and more.
DNS Health Check
Run a comprehensive DNS health check on your domain. Analyze nameservers, SOA, MX, web records, and email authentication.
Frequently Asked Questions
-
It connects to the server over SSL/TLS, downloads the certificate, and analyzes it – showing the issuer, validity period, subject alternative names (SANs), certificate chain, and encryption details.
-
It shows how many days until the SSL certificate expires. Certificates should be renewed before expiration to avoid browser security warnings.
-
A certificate chain links your server’s SSL certificate to a trusted root certificate authority (CA) through one or more intermediate certificates. If the chain is incomplete, browsers may show security warnings even if the certificate itself is valid.
-
Common causes: expired certificate, certificate issued for a different domain, incomplete certificate chain, mixed content (HTTP resources on an HTTPS page), or no SSL certificate installed at all. Use this tool to identify the specific issue.
-
Most certificates issued today are valid for 90 days (Let's Encrypt) or 1 year (commercial CAs). Set up automatic renewal if possible. Check your certificate regularly – an expired certificate will show security warnings to all visitors.