A name "server-daten.de" is domain, public suffix is "de", top-level-domain-type is "country-code", Country is Germany, tld-manager is "DENIC eG" A good: All ip addresses are public addresses A good: No asked Authoritative Name Server had a timeout A good: destination is https A good - only one version with Http-Status 200 A good: one preferred version: www is preferred A good: every cookie sent via https is marked as secure A good: every https has a Strict Transport Security Header A good: HSTS max-age is long enough, 63072000 seconds = 730 days A good: HSTS has includeSubdomains - directive A good: HSTS has preload directive A Excellent: Domain is in the Google-Preload-List A Excellent: Domain is in the Mozilla/Firefox-Preload-List A HSTS-Preload-Status: Preloaded. Check https://hstspreload.org/ to learn some basics about the Google-Preload-List. A Good: All urls with http status 200/404 have a complete Content-Type header (MediaType / MediaSubType + correct charset) A http://server-daten.de/ 85.215.2.226 https://server-daten.de/ correct redirect http - https with the same domain name A http://server-daten.de/ 2a01:238:301b::1226 https://server-daten.de/ correct redirect http - https with the same domain name A http://www.server-daten.de/ 85.215.2.226 https://www.server-daten.de/ correct redirect http - https with the same domain name A http://www.server-daten.de/ 2a01:238:301b::1226 https://www.server-daten.de/ correct redirect http - https with the same domain name A Good: Nameserver supports TCP connections: 10 good Nameserver A Good: Nameserver supports Echo Capitalization: 10 good Nameserver A Good: Nameserver supports EDNS with max. 512 Byte Udp payload, message is smaller: 10 good Nameserver A Good: Nameserver has passed 10 EDNS-Checks (OP100, FLAGS, V1, V1OP100, V1FLAGS, DNSSEC, V1DNSSEC, NSID, COOKIE, CLIENTSUBNET): 4 good Nameserver Nameserver doesn't pass all EDNS-Checks: ns3.inwx.eu / 46.165.212.97: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok (krabappel.inwx.net). COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns3.inwx.eu / 2a00:c98:2100:a006:3::1: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok (krabappel.inwx.net). COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns4.inwx.com / 95.211.1.145: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok (hoover). COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns4.inwx.com / 2001:1af8:4400:a048:1::1: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok (hoover). COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns5.inwx.net / 108.59.8.65: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok (chalmers.inwx.net). COOKIE: ok. CLIENTSUBNET: ok. Nameserver doesn't pass all EDNS-Checks: ns5.inwx.net / 2604:9a00:2010:a013:1::1: OP100: ok. FLAGS: ok. V1: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. V1OP100: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found, no OPT100 expected, no OPT100 found. V1FLAGS: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. DNSSEC: ok. V1DNSSEC: SOA NOT expected, but found, BADVER expected, NOERR found, Version 0 expectend and found. NSID: ok (chalmers.inwx.net). COOKIE: ok. CLIENTSUBNET: ok. A Good: All SOA have the same Serial Number A Good: Consistency between delegation and zone. The set of NS records served by the authoritative name servers must match those proposed for the delegation in the parent zone. Ordered list of name servers: ns.inwx.de,ns2.inwx.de,ns3.inwx.eu,ns4.inwx.com,ns5.inwx.net A good: CAA entries found, creating certificate is limited: letsencrypt.org is allowed to create certificates A Good: All checks /.well-known/acme-challenge/random-filename without redirects answer with the expected http status 404 - Not Found. Creating a Letsencrypt certificate via http-01 challenge should work. If it doesn't work: Check your vHost configuration (apachectl -S, httpd -S, nginx -T). Every combination of port and ServerName / ServerAlias (Apache) or Server (Nginx) must be unique. Merge duplicated entries in one vHost. If you use an IIS, extensionless files must be allowed in the /.well-known/acme-challenge subdirectory. Create a web.config in that directory. Content: <configuration><system.webServer><staticContent><mimeMap fileExtension="." mimeType="text/plain" /></staticContent></system.webServer></configuration>. If you have a redirect http ⇒ https, that's ok, Letsencrypt follows such redirects to port 80 / 443 (same or other server). There must be a certificate. But the certificate may be expired, self signed or with a not matching domain name. Checking the validation file Letsencrypt ignores such certificate errors. Trouble creating a certificate? Use https://community.letsencrypt.org/ to ask. A Good: Every https result with status 200 supports GZip. A Good: No https + http status 200 with inline CSS / JavaScript found A Good: Every https result with status 200 has a minified Html-Content with a quota lower then 110 %. A Good: Every https connection via port 443 supports the http/2 protocol via ALPN. A Good: All CSS / JavaScript files are sent with GZip. That reduces the content of the files. 4 external CSS / JavaScript files found A Good: All images with internal compression not sent via GZip. Images (.png, .jpg) are already compressed, so an additional GZip isn't helpful. 2 images (type image/png, image/jpg) found without additional GZip. Not required because these images are already compressed A Good: All CSS / JavaScript files are sent with a long Cache-Control header (minimum 7 days). So the browser can re-use these files, no download is required. 4 external CSS / JavaScript files with long Cache-Control max-age found A Good: All images are sent with a long Cache-Control header (minimum 7 days). So the browser can reuse these files, no download is required. 2 image files with long Cache-Control max-age found A Good: All checked attribute values are enclosed in quotation marks (" or '). A Good: All img-elements have a valid alt-attribute.: 2 img-elements found. A Good: Domainname is not on the "Specially Designated Nationals And Blocked Persons List" (SDN). That's an US-list of individuals and companies owned or controlled by, or acting for or on behalf of, targeted countries. It also lists individuals, groups, and entities, such as terrorists and narcotics traffickers designated under programs that are not country-specific. Collectively, such individuals and companies are called "Specially Designated Nationals" or "SDNs." Their assets are blocked and U.S. persons are generally prohibited from dealing with them. So if a domain name is on that list, it's impossible to create a Letsencrypt certificate with that domain name. Check the list manual - https://www.treasury.gov/resource-center/sanctions/sdn-list/pages/default.aspx A Duration: 87643 milliseconds, 87.643 seconds