1. General Results, most used to calculate the result A name "app.navidrome.cloudbilingual.com" is subdomain, public suffix is ".com", top-level-domain is ".com", top-level-domain-type is "generic", tld-manager is "VeriSign Global Registry Services", num .com-domains preloaded: 89449 (complete: 231048) A Good: All ip addresses are public addresses Warning: Only one ip address found: app.navidrome.cloudbilingual.com has only one ip address. Warning: No ipv6 address found. Ipv6 is the future with a lot of new features. So every domain name should have an ipv6 address. See https://en.wikipedia.org/wiki/IPv6: app.navidrome.cloudbilingual.com has no ipv6 address. A Good: No asked Authoritative Name Server had a timeout A DNS: "Name Error" means: No www-dns-entry defined. This isn't a problem A https://app.navidrome.cloudbilingual.com/ 3.104.101.254 https://app.navidrome.cloudbilingual.com/app/ Correct redirect https to https A https://3.104.101.254/ 3.104.101.254 https://app.navidrome.cloudbilingual.com/app/ Correct redirect https to https A Good: destination is https A Good - only one version with Http-Status 200 A Good: one preferred version: non-www is preferred HSTS-Preload-Status: unknown. Domain never included in the Preload-list. Check https://hstspreload.org/ to learn some basics about the Google-Preload-List. A Good: Some urls with http status 200/404 have a complete Content-Type header (MediaType / MediaSubType + correct charset):0 complete Content-Type - header (1 urls) https://app.navidrome.cloudbilingual.com/app/ Url with incomplete Content-Type - header - missing charset B https://app.navidrome.cloudbilingual.com/ 3.104.101.254 Missing HSTS-Header B https://app.navidrome.cloudbilingual.com/app/ Missing HSTS-Header N https://app.navidrome.cloudbilingual.com/ 3.104.101.254 https://app.navidrome.cloudbilingual.com/app/ Error - Certificate isn't trusted, RemoteCertificateChainErrors N https://app.navidrome.cloudbilingual.com/app/ Error - Certificate isn't trusted, RemoteCertificateChainErrors N https://3.104.101.254/ 3.104.101.254 https://app.navidrome.cloudbilingual.com/app/ Error - Certificate isn't trusted, RemoteCertificateNameMismatch, RemoteCertificateChainErrors O app.navidrome.cloudbilingual.com / 3.104.101.254 / 443 Old connection: Cipher Suites without Forward Secrecy (FS) found. Remove all of these Cipher Suites, use only Cipher Suites with Forward Secrecy: Starting with ECDHE- or DHE - the last "E" says: "ephemeral". Or use Tls.1.3, then all Cipher Suites use FS. 16 Cipher Suites without Forward Secrecy found Info: Checking all ip addresses of that domain without sending the hostname only one certificate found. Checking all ip addresses and sending the hostname only one certificate found. Both certificates are the same. So that domain doesn't require Server Name Indication (SNI), it's the primary certificate of that set of ip addresses.: Domain app.navidrome.cloudbilingual.com, 1 ip addresses, 1 different http results. B No _mta-sts TXT record found (mta-sts: Mail Transfer Agent Strict Transport Security - see RFC 8461). Read the result of server-daten.de (Url-Checks, Comments, Connections and DomainServiceRecords) to see a complete definition. Domainname: _mta-sts.app.navidrome.cloudbilingual.com 2. Header-Checks A app.navidrome.cloudbilingual.com X-Content-Type-Options Ok: Header without syntax errors found: nosniff A Referrer-Policy Ok: Header without syntax errors found: same-origin A Permissions-Policy Ok: Header without syntax errors found: autoplay=(), camera=(), microphone=(), usb=() A X-Frame-Options Ok: Header without syntax errors found: DENY B Info: Header is deprecated. May not longer work in modern browsers. DENY. Better solution: Use a Content-Security-Policy Header with a frame-ancestors directive. DENY - use 'none', SAMEORIGIN - use 'self'. If you want to allow some domains to frame your page, add these urls. F app.navidrome.cloudbilingual.com Content-Security-Policy Critical: Missing Header: 3. DNS- and NameServer - Checks A Info:: 16 Root-climbing DNS Queries required to find all IPv4- and IPv6-Addresses of 4 Name Servers. A Info:: 16 Queries complete, 16 with IPv6, 0 with IPv4. A Good: All DNS Queries done via IPv6. Ok (4 - 8):: An average of 4.0 queries per domain name server required to find all ip addresses of all name servers. A Info:: 4 different Name Servers found: ns-1199.awsdns-21.org, ns-1699.awsdns-20.co.uk, ns-93.awsdns-11.com, ns-962.awsdns-56.net, 4 Name Servers included in Delegation: ns-1199.awsdns-21.org, ns-1699.awsdns-20.co.uk, ns-93.awsdns-11.com, ns-962.awsdns-56.net, 4 Name Servers included in 1 Zone definitions: ns-1199.awsdns-21.org, ns-1699.awsdns-20.co.uk, ns-93.awsdns-11.com, ns-962.awsdns-56.net, 1 Name Servers listed in SOA.Primary: ns-1699.awsdns-20.co.uk. A Good: Only one SOA.Primary Name Server found.: ns-1699.awsdns-20.co.uk. A Good: SOA.Primary Name Server included in the delegation set.: ns-1699.awsdns-20.co.uk. 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-1199.awsdns-21.org, ns-1699.awsdns-20.co.uk, ns-93.awsdns-11.com, ns-962.awsdns-56.net A Good: All Name Server Domain Names have a Public Suffix. A Good: All Name Server Domain Names ending with a Public Suffix have minimal one IPv4- or IPv6 address. A Good: All Name Server ip addresses are public. A Good: Minimal 2 different name servers (public suffix and public ip address) found: 4 different Name Servers found A Good: All name servers have ipv4- and ipv6-addresses.: 4 different Name Servers found A Good: Name servers with different Top Level Domains / Public Suffix List entries found: 4 Name Servers, 4 Top Level Domains: org, net, com, co.uk A Good: Name Servers with different domain names found.: 4 different Domains found A Good: Name servers with different Country locations found: 4 Name Servers, 3 Countries: GB, IE, US A Info: Ipv4-Subnet-list: 4 Name Servers, 1 different subnets (first Byte): 205., 1 different subnets (first two Bytes): 205.251., 4 different subnets (first three Bytes): 205.251.192., 205.251.195., 205.251.196., 205.251.198. A Good: Name Server IPv4-addresses from different subnet found: A Info: IPv6-Subnet-list: 4 Name Servers with IPv6, 1 different subnets (first block): 2600:, 1 different subnets (first two blocks): 2600:9000:, 4 different subnets (first three blocks): 2600:9000:5300:, 2600:9000:5303:, 2600:9000:5304:, 2600:9000:5306:, 4 different subnets (first four blocks): 2600:9000:5300:5d00:, 2600:9000:5303:c200:, 2600:9000:5304:af00:, 2600:9000:5306:a300: A Good: Name Server IPv6 addresses from different subnets found. A Good: Nameserver supports TCP connections: 2 good Nameserver A Good: Nameserver supports Echo Capitalization: 2 good Nameserver A Good: Nameserver supports EDNS with max. 512 Byte Udp payload, message is smaller: 2 good Nameserver A Good: Nameserver has passed 10 EDNS-Checks (OP100, FLAGS, V1, V1OP100, V1FLAGS, DNSSEC, V1DNSSEC, NSID, COOKIE, CLIENTSUBNET): 2 good Nameserver Nameserver doesn't pass all EDNS-Checks: ns-1699.awsdns-20.co.uk: OP100: no result. FLAGS: no result. V1: no result. V1OP100: no result. V1FLAGS: no result. DNSSEC: no result. V1DNSSEC: no result. NSID: no result. COOKIE: no result. CLIENTSUBNET: no result. Nameserver doesn't pass all EDNS-Checks: ns-1699.awsdns-20.co.uk: OP100: no result. FLAGS: no result. V1: no result. V1OP100: no result. V1FLAGS: no result. DNSSEC: no result. V1DNSSEC: no result. NSID: no result. COOKIE: no result. CLIENTSUBNET: no result. A Good: All SOA have the same Serial Number Warning: No CAA entry with issue/issuewild found, every CAA can create a certificate. Read https://en.wikipedia.org/wiki/DNS_Certification_Authority_Authorization to learn some basics about the idea of CAA. Your name server must support such an entry. Not all dns providers support CAA entries. 4. Content- and Performance-critical Checks http://app.navidrome.cloudbilingual.com/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 3.104.101.254 Fatal: Check of /.well-known/acme-challenge/random-filename has a timeout. Creating a Letsencrypt certificate via http-01 challenge can't work. You need a running webserver (http) and an open port 80. If it's a home server + ipv4, perhaps a correct port forwarding port 80 extern ⇒ working port intern is required. Port 80 / http can redirect to another domain port 80 or port 443, but not other ports. If it's a home server, perhaps your ISP blocks port 80. Then you may use the dns-01 challenge. Trouble creating a certificate? Use https://community.letsencrypt.org/ to ask. A Good: Every https result with status 200 supports GZip. https://app.navidrome.cloudbilingual.com/app/ Warning: Https + http status 200 + Inline CSS / JavaScript found. Don't use inline CSS / JavaScript. These are compiled and re-used ressources, save these with a long Cache-Control max-age - header. https://app.navidrome.cloudbilingual.com/app/ Warning: Https result with status 200 found, Html-Content is too big. Should be max. 110 %. May contain inline CSS / JavaScript, too much comments or white space. Re-used ressources - create files with a long Cache-Control max-age header. Remove comments and white space. https://app.navidrome.cloudbilingual.com/app/ Warning: Https connections (Standard Port 443) found without support of the http/2 protocol via ALPN. Http/2 is the new Http-Version (old: http 1.1) with some important new features. Update your server software so http/2 is available. Only one TCP-connection per Server (that's a performance boost), Header-Compression and Server Pushs are available. Domain Sharding and Inline-CSS/Javascript shouldn't used with http/2. A Good: All script Elements (type text/javascript) and src-Attribute have a defer / async - Attribute. So loading and executing these JavaScripts doesn't block parsing and rendering the Html-Output. A Good: All CSS / JavaScript files are sent with GZip. That reduces the content of the files. 2 external CSS / JavaScript files found Warning: CSS / JavaScript files with a missing or too short Cache-Control header found. Browsers should cache and re-use these files. 2 external CSS / JavaScript files without Cache-Control-Header, 0 with Cache-Control, but no max-age, 0 with Cache-Control max-age too short (minimum 7 days), 0 with Cache-Control long enough, 2 complete. A Good: All checked attribute values are enclosed in quotation marks (" or '). A Info: No img element found, no alt attribute checked 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: 348620 milliseconds, 348.620 seconds