Why check your SSL certificate?
Browsers block or warn on sites whose certificate has expired, does not cover the hostname, or comes from an untrusted issuer. Most certificates today are valid for 90 days or less, so automatic renewal can fail quietly — a full disk, a changed DNS record or a firewall rule is enough.
This checker connects to the site on port 443, reads the certificate it presents and shows the issuer, validity window, days left and every hostname listed in the Subject Alternative Name (SAN) field.
Frequently asked questions
How many days before expiry should I renew an SSL certificate?
With automated ACME clients such as certbot, renewal normally runs when about 30 days remain. For manually installed certificates, start at least two weeks early so you have time for validation and installation on every server.
Why does my certificate look valid here but the browser shows an error?
The browser may be checking a different hostname (for example www vs. the bare domain), a missing intermediate certificate, or a cached old certificate on a CDN. Make sure the hostname appears in the SAN list and the full chain is installed.
Is a free certificate as secure as a paid one?
Encryption strength is the same. Paid OV/EV certificates add organisation validation and support, but browsers show no special indicator for them anymore. For most sites a free DV certificate from Let’s Encrypt or a hosting provider is enough.
Can I get reminded before my SSL certificate expires?
Yes. Track the domain on TLDix for free and we email you 30, 7 and 1 day before the certificate or the domain registration expires.