The certificates that Let&#x27;s Encrypt issues are cross-signed by IdenTrust (a real CA) so browsers should trust the certificate you get from Let&#x27;s Encrypt. NOTE: just like with other TLS certs, you will need to include the Let&#x27;s Encrypt intermediate certificate in your webserver config so that it can be chained back to IdenTrust.<p>EDIT: IdenTrust, not Entrust, sorry!