What is TLS?
TLS (Transport Layer Security) is the encryption protocol behind HTTPS. It keeps data between a visitor’s browser and your server private and tamper-evident.
Why businesses care
Expired certificates or outdated TLS versions produce browser warnings and weaken protection for customer logins and payments.
Example
A site negotiating TLS 1.3 with a valid certificate issued by a public certificate authority.How to check
Open your site and inspect the certificate, or run the SSL checker.
How to fix
Use a certificate with auto-renewal and allow only TLS 1.2 and 1.3.
Common mistakes
- Letting a certificate expire
- Missing intermediate certificates
- Supporting TLS 1.0/1.1
Sources
Check it with SSL/TLS Certificate Checker
Check your SSL/TLS certificate: trusted or not, days until expiry, issuer and the TLS version your server negotiates. Free.
Open SSL/TLS Certificate Checker