Networks
Security certificate
In Turkish: Güvenlik sertifikası
A digital document that lets a site prove who it is to your browser. A certificate warning means that proof failed.
When you open a site, your browser checks its certificate. If it is expired, issued for another name, or not trusted, you see a full-page warning. Sometimes the cause is harmless, like a wrong clock on your device. But it can also mean someone on the network is sitting between you and the site.
On a site you know well, do not click "continue anyway". Try another network, such as mobile data. If the warning disappears, the first network was the problem.
What to do
- Stop and do not log in when a certificate warning appears on a familiar site.
- Switch to mobile data and try again.
- Check that your device's date and time are correct.
Related terms
Learn it in the Academy
Try it
Free tools that put this to use.
- Website security check
Grade a website's security headers, HTTPS and protection against forged email.