{
    "ok": true,
    "domain": "duolingo.com",
    "generated_at": "2026-08-08T20:31:43-05:00",
    "cache": {
        "hit": true,
        "ttl": 0
    },
    "score": {
        "total": 80,
        "label": "Good",
        "categories": {
            "dns": 70,
            "mail": 90,
            "security": 69,
            "network": 65,
            "availability": 100
        },
        "category_weights": {
            "dns": 25,
            "mail": 20,
            "security": 25,
            "network": 10,
            "availability": 20
        },
        "items": [
            {
                "category": "dns",
                "title": "IPv4 (A)",
                "max_points": 30,
                "earned_points": 30,
                "lost_points": 0,
                "detail": "3 IPv4 address(es) detected."
            },
            {
                "category": "dns",
                "title": "IPv6 (AAAA)",
                "max_points": 10,
                "earned_points": 0,
                "lost_points": 10,
                "detail": "0 IPv6 address(es) detected."
            },
            {
                "category": "dns",
                "title": "Name server redundancy",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0,
                "detail": "4 NS record(s); 2 or more required."
            },
            {
                "category": "dns",
                "title": "SOA record",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0,
                "detail": "Authoritative zone record."
            },
            {
                "category": "dns",
                "title": "DNSSEC chain",
                "max_points": 15,
                "earned_points": 0,
                "lost_points": 15,
                "detail": "Both DS and DNSKEY are required."
            },
            {
                "category": "dns",
                "title": "CAA policy",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5,
                "detail": "Certificate authority restriction."
            },
            {
                "category": "dns",
                "title": "DNS propagation",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0,
                "detail": "Agreement between public resolvers."
            },
            {
                "category": "mail",
                "title": "MX records",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0,
                "detail": "7 MX record(s)."
            },
            {
                "category": "mail",
                "title": "SPF",
                "max_points": 25,
                "earned_points": 25,
                "lost_points": 0,
                "detail": "SPF policy published."
            },
            {
                "category": "mail",
                "title": "DMARC",
                "max_points": 25,
                "earned_points": 25,
                "lost_points": 0,
                "detail": "DMARC policy published."
            },
            {
                "category": "mail",
                "title": "DKIM",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0,
                "detail": "A DKIM selector was verified."
            },
            {
                "category": "mail",
                "title": "MTA-STS",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5,
                "detail": "Mail transport policy."
            },
            {
                "category": "mail",
                "title": "TLS-RPT",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5,
                "detail": "TLS reporting policy."
            },
            {
                "category": "security",
                "title": "Valid TLS certificate",
                "max_points": 55,
                "earned_points": 55,
                "lost_points": 0,
                "detail": "137 day(s) remaining."
            },
            {
                "category": "security",
                "title": "Certificate lifetime",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0,
                "detail": "Full points require at least 30 days remaining."
            },
            {
                "category": "security",
                "title": "HTTP security headers",
                "max_points": 35,
                "earned_points": 4,
                "lost_points": 31,
                "detail": "1 of 9 evaluated headers detected."
            },
            {
                "category": "network",
                "title": "PTR reverse DNS",
                "max_points": 30,
                "earned_points": 30,
                "lost_points": 0,
                "detail": "PTR: ec2-50-17-4-40.compute-1.amazonaws.com"
            },
            {
                "category": "network",
                "title": "IPv4 diversity",
                "max_points": 35,
                "earned_points": 35,
                "lost_points": 0,
                "detail": "Two or more IPv4 addresses receive full points."
            },
            {
                "category": "network",
                "title": "IPv6 connectivity",
                "max_points": 35,
                "earned_points": 0,
                "lost_points": 35,
                "detail": "AAAA availability."
            },
            {
                "category": "availability",
                "title": "DNS resolution",
                "max_points": 40,
                "earned_points": 40,
                "lost_points": 0,
                "detail": "At least one address family must resolve."
            },
            {
                "category": "availability",
                "title": "HTTP response",
                "max_points": 40,
                "earned_points": 40,
                "lost_points": 0,
                "detail": "HTTP/2 200 "
            },
            {
                "category": "availability",
                "title": "HTTPS final URL",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0,
                "detail": "Final URL uses HTTPS."
            }
        ],
        "methodology": "Each category is normalized to 100. The total is the weighted sum: DNS 25%, Email 20%, Security 25%, Network 10%, Availability 20%.",
        "diagnostics": [
            {
                "level": "ok",
                "title": "IPv4 (A)",
                "detail": "3 IPv4 address(es) detected.",
                "category": "dns",
                "max_points": 30,
                "earned_points": 30,
                "lost_points": 0
            },
            {
                "level": "error",
                "title": "IPv6 (AAAA)",
                "detail": "0 IPv6 address(es) detected.",
                "category": "dns",
                "max_points": 10,
                "earned_points": 0,
                "lost_points": 10
            },
            {
                "level": "ok",
                "title": "Name server redundancy",
                "detail": "4 NS record(s); 2 or more required.",
                "category": "dns",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "SOA record",
                "detail": "Authoritative zone record.",
                "category": "dns",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0
            },
            {
                "level": "error",
                "title": "DNSSEC chain",
                "detail": "Both DS and DNSKEY are required.",
                "category": "dns",
                "max_points": 15,
                "earned_points": 0,
                "lost_points": 15
            },
            {
                "level": "error",
                "title": "CAA policy",
                "detail": "Certificate authority restriction.",
                "category": "dns",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5
            },
            {
                "level": "ok",
                "title": "DNS propagation",
                "detail": "Agreement between public resolvers.",
                "category": "dns",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "MX records",
                "detail": "7 MX record(s).",
                "category": "mail",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "SPF",
                "detail": "SPF policy published.",
                "category": "mail",
                "max_points": 25,
                "earned_points": 25,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "DMARC",
                "detail": "DMARC policy published.",
                "category": "mail",
                "max_points": 25,
                "earned_points": 25,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "DKIM",
                "detail": "A DKIM selector was verified.",
                "category": "mail",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0
            },
            {
                "level": "error",
                "title": "MTA-STS",
                "detail": "Mail transport policy.",
                "category": "mail",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5
            },
            {
                "level": "error",
                "title": "TLS-RPT",
                "detail": "TLS reporting policy.",
                "category": "mail",
                "max_points": 5,
                "earned_points": 0,
                "lost_points": 5
            },
            {
                "level": "ok",
                "title": "Valid TLS certificate",
                "detail": "137 day(s) remaining.",
                "category": "security",
                "max_points": 55,
                "earned_points": 55,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "Certificate lifetime",
                "detail": "Full points require at least 30 days remaining.",
                "category": "security",
                "max_points": 10,
                "earned_points": 10,
                "lost_points": 0
            },
            {
                "level": "warning",
                "title": "HTTP security headers",
                "detail": "1 of 9 evaluated headers detected.",
                "category": "security",
                "max_points": 35,
                "earned_points": 4,
                "lost_points": 31
            },
            {
                "level": "ok",
                "title": "PTR reverse DNS",
                "detail": "PTR: ec2-50-17-4-40.compute-1.amazonaws.com",
                "category": "network",
                "max_points": 30,
                "earned_points": 30,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "IPv4 diversity",
                "detail": "Two or more IPv4 addresses receive full points.",
                "category": "network",
                "max_points": 35,
                "earned_points": 35,
                "lost_points": 0
            },
            {
                "level": "error",
                "title": "IPv6 connectivity",
                "detail": "AAAA availability.",
                "category": "network",
                "max_points": 35,
                "earned_points": 0,
                "lost_points": 35
            },
            {
                "level": "ok",
                "title": "DNS resolution",
                "detail": "At least one address family must resolve.",
                "category": "availability",
                "max_points": 40,
                "earned_points": 40,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "HTTP response",
                "detail": "HTTP/2 200 ",
                "category": "availability",
                "max_points": 40,
                "earned_points": 40,
                "lost_points": 0
            },
            {
                "level": "ok",
                "title": "HTTPS final URL",
                "detail": "Final URL uses HTTPS.",
                "category": "availability",
                "max_points": 20,
                "earned_points": 20,
                "lost_points": 0
            }
        ]
    },
    "dns": {
        "records": {
            "A": [
                "50.17.4.40",
                "52.4.137.170",
                "100.61.158.178"
            ],
            "AAAA": [],
            "CNAME": [],
            "MX": [
                "30 aspmx5.googlemail.com.",
                "20 alt1.aspmx.l.google.com.",
                "30 aspmx4.googlemail.com.",
                "10 aspmx.l.google.com.",
                "30 aspmx3.googlemail.com.",
                "30 aspmx2.googlemail.com.",
                "20 alt2.aspmx.l.google.com."
            ],
            "TXT": [
                "\"pardot_208162_*=c15d5cb1b9f31e26058e1f30bda9e5d65c57cfeea37b34af8e1dd88474460e90\"",
                "\"anthropic-domain-verification-z4335b=YssTBALPY7K784Sri4FjVHjd3\"",
                "\"atlassian-sending-domain-verification=423a5faf-1cfa-4704-a38a-f7adae302dd6\"",
                "\"_vg2bua41v8x489g1y55hg3hr4h3qmj0\"",
                "\"apple-domain-verification=bMPI889zOgALUenN\"",
                "\"klaviyo-site-verification=RKdcF3\"",
                "\"klaviyo-site-verification=TGmZS7\"",
                "\"docker-verification=b4ead4c5-fd66-42a5-a684-8f2e7f4c1417\"",
                "\"openai-domain-verification=dv-ieCpefZUqvVQwb8f7o4SlFye\"",
                "\"slack-domain-verification=iuNWYimCCkEpnistAJvWc4YOZF8izoZ23TCDek0I\"",
                "\"rippling-domain-verification=9692f0635321f04d\"",
                "\"h1-domain-verification=sjPBeaGqQwEe8YhJ3W8JVNJa7WDQFAzc6AHkURoErkh324Yy\"",
                "\"e622flctk14s3cs3ccdauh8uth\"",
                "\"spacelift-domain-verification=519xtPXm\"",
                "\"MS=ms66530579\"",
                "\"openai-domain-verification=dv-A4cFxdrYIEodfG6UiQU0qxnT\"",
                "\"google-site-verification=975UaH3lkKONB88HjWDDg34p8cdCqyTVSq_KGBAXrmU\"",
                "\"pardot_208162_*=610bfb45f202232a79db94c298b30d14332a62a6894e695b025fa7949d7b03fa\"",
                "\"aliyun-site-verification=1acfc148-50be-45c8-a021-3c933fc8eff9\"",
                "\"jetbrains-domain-verification=bt8q7duih10l9pmf5fo5yy8wf\"",
                "\"v=spf1 ip4:100.25.59.11 ip4:205.201.128.0/20 ip4:198.2.128.0/18 ip4:148.105.8.0/21 ip4:52.73.203.75 ip4:52.70.130.33 include:amazonses.com include:_spf.google.com include:_spf.salesforce.com include:mail.zendesk.com include:aspmx.pardot.com ~all\"",
                "\"amazonses:+SIz2NZPqYri3C+PSIyKShZIbuI4rNpbLlES7lmvpu4=\"",
                "\"stripe-verification=c8d270a115adc8c5a0a84fb24e17b7d05f66aad648d01e86f15548c6d0254ff5\""
            ],
            "NS": [
                "ns-247.awsdns-30.com.",
                "ns-1117.awsdns-11.org.",
                "ns-1904.awsdns-46.co.uk.",
                "ns-1020.awsdns-63.net."
            ],
            "SOA": [
                "ns-1020.awsdns-63.net. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400"
            ],
            "CAA": [],
            "DS": [],
            "DNSKEY": [],
            "RRSIG": [],
            "NSEC": [],
            "NSEC3": [],
            "SRV": [],
            "NAPTR": [],
            "TLSA": [],
            "SSHFP": []
        },
        "ipv4": [
            "50.17.4.40",
            "52.4.137.170",
            "100.61.158.178"
        ],
        "ipv6": []
    },
    "mail": {
        "spf": "v=spf1 ip4:100.25.59.11 ip4:205.201.128.0/20 ip4:198.2.128.0/18 ip4:148.105.8.0/21 ip4:52.73.203.75 ip4:52.70.130.33 include:amazonses.com include:_spf.google.com include:_spf.salesforce.com include:mail.zendesk.com include:aspmx.pardot.com ~all",
        "dmarc": "v=DMARC1; p=reject; sp=reject; fo=1; rua=mailto:re+lhqmqj57zra@DMARC.postmarkapp.com,mailto:re+xu5r3a1wrlo@inbound.dmarcdigests.com,mailto:dmarcreports@duolingo.com; ruf=mailto:dmarcreports@duolingo.com; adkim=r; aspf=r",
        "dkim_selector": "google",
        "dkim_host": "google._domainkey.duolingo.com",
        "dkim": "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCzNuM4gb1XRWRkI3wae2j3rWxEeNf9NkV0QkP7GZQ60sw5RrLfL1IOTMoBO+gaHmbCIN3q+MMvr6IDFDCowE8XXKe+FTeElZygkddZmo2I34I7MkD01A1xSEu/jIsSLzQyo4IgM3s+d+jO6QlsgjK1dovZFA6N3fcxXaR3UoqXZwIDAQAB",
        "spf_analysis": {
            "valid": true,
            "lookups": 5,
            "final": "~all",
            "message": "Within the estimated limit"
        },
        "dmarc_analysis": {
            "valid": true,
            "policy": "reject"
        },
        "bimi": "v=BIMI1;l=https://vmc.digicert.com/48d5bb87-18e0-4bf9-afdc-3b7e4aaae06b.svg;a=https://vmc.digicert.com/48d5bb87-18e0-4bf9-afdc-3b7e4aaae06b.pem",
        "mta_sts": "",
        "tls_rpt": ""
    },
    "advanced": {
        "ptr": "ec2-50-17-4-40.compute-1.amazonaws.com",
        "propagation": {
            "consistent": true,
            "results": [
                {
                    "provider": "Google",
                    "server": "8.8.8.8",
                    "result": [
                        "100.61.158.178",
                        "50.17.4.40",
                        "52.4.137.170"
                    ],
                    "time_ms": 70.26
                },
                {
                    "provider": "Cloudflare",
                    "server": "1.1.1.1",
                    "result": [
                        "100.61.158.178",
                        "50.17.4.40",
                        "52.4.137.170"
                    ],
                    "time_ms": 28.82
                },
                {
                    "provider": "Quad9",
                    "server": "9.9.9.9",
                    "result": [
                        "100.61.158.178",
                        "50.17.4.40",
                        "52.4.137.170"
                    ],
                    "time_ms": 42.81
                },
                {
                    "provider": "OpenDNS",
                    "server": "208.67.222.222",
                    "result": [
                        "100.61.158.178",
                        "50.17.4.40",
                        "52.4.137.170"
                    ],
                    "time_ms": 27.63
                },
                {
                    "provider": "AdGuard",
                    "server": "94.140.14.14",
                    "result": [
                        "100.61.158.178",
                        "50.17.4.40",
                        "52.4.137.170"
                    ],
                    "time_ms": 66.72
                }
            ]
        }
    },
    "ssl": {
        "available": true,
        "issuer": "Amazon",
        "subject": "duolingo.com",
        "valid_from": "2025-11-24T18:00:00-06:00",
        "valid_to": "2026-12-24T17:59:59-06:00",
        "days_remaining": 137,
        "san": [
            "duolingo.com"
        ],
        "protocol": "TLSv1.2",
        "cipher": "ECDHE-RSA-AES128-GCM-SHA256"
    },
    "http": {
        "url": "https://www.duolingo.com/",
        "status": "HTTP/2 200 ",
        "http_version": "3",
        "headers": {
            "date": "Sun, 09 Aug 2026 01:31:34 GMT",
            "content-type": "text/html; charset=UTF-8",
            "content-length": "11248",
            "location": "https://www.duolingo.com/",
            "server": "duo-api",
            "x-duo-request-host": "www.duolingo.com",
            "set-cookie": "wuuid=093c12a3-5b32-48c4-8b02-85f3fa448c6d",
            "no-retry": "1",
            "cache-control": "no-store, no-cache, must-revalidate, proxy-revalidate",
            "expires": "0",
            "pragma": "no-cache",
            "surrogate-control": "no-store",
            "x-frame-options": "SAMEORIGIN",
            "x-tid": "fffff16c6a77c82d1c73",
            "x-ws": "UK",
            "x-runtime": "0.01845",
            "x-envoy-upstream-service-time": "21",
            "x-cache": "Miss from cloudfront",
            "via": "1.1 c3a41271ff94252c37829a4b31f066ec.cloudfront.net (CloudFront)",
            "x-amz-cf-pop": "ORD58-P13",
            "x-amz-cf-id": "LtFMNYSwhBVTllqpmoGXay17CoskTloUMJTw7n95l-1r7v4LVubR_Q=="
        },
        "security_checks": {
            "strict-transport-security": false,
            "content-security-policy": false,
            "x-content-type-options": false,
            "x-frame-options": true,
            "referrer-policy": false,
            "permissions-policy": false,
            "cross-origin-opener-policy": false,
            "cross-origin-embedder-policy": false,
            "cross-origin-resource-policy": false
        },
        "server": "duo-api",
        "powered_by": ""
    },
    "webpage": {
        "url": "https://www.duolingo.com/",
        "title": "Duolingo",
        "description": "Duolingo is the world's most popular way to learn a language. It's 100% free, fun and science-based. Practice online on duolingo.com or on the apps!",
        "success": true,
        "error": "",
        "status": 200
    },
    "network": {
        "50.17.4.40": {
            "success": false,
            "country": "",
            "region": "",
            "city": "",
            "asn": "",
            "organization": "",
            "isp": ""
        },
        "52.4.137.170": {
            "success": false,
            "country": "",
            "region": "",
            "city": "",
            "asn": "",
            "organization": "",
            "isp": ""
        },
        "100.61.158.178": {
            "success": false,
            "country": "",
            "region": "",
            "city": "",
            "asn": "",
            "organization": "",
            "isp": ""
        }
    },
    "smtp": {
        "host": "aspmx5.googlemail.com",
        "ports": [
            {
                "port": 25,
                "open": false,
                "time_ms": 32.5,
                "banner": "",
                "error": "Network is unreachable"
            },
            {
                "port": 465,
                "open": false,
                "time_ms": 4043.4,
                "banner": "",
                "error": "Connection timed out"
            },
            {
                "port": 587,
                "open": false,
                "time_ms": 4019.9,
                "banner": "",
                "error": "Connection timed out"
            }
        ]
    },
    "visitor": {
        "ip": "216.73.217.62",
        "reverse": "",
        "country": "",
        "country_code": "",
        "region": "",
        "city": "",
        "latitude": null,
        "longitude": null,
        "isp": "",
        "organization": "",
        "asn": "",
        "timezone": "",
        "browser": "Other",
        "os": "Other",
        "language": "",
        "user_agent": "Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)",
        "is_bot": true,
        "cloudflare": false
    },
    "analysis_time_ms": 94.86
}