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DNS Checker(beta)

API Documentation

The dnschkr API provides programmatic access to WHOIS, DNS, IP intelligence, and email security tools. Build integrations, monitor domains, and automate lookups with a simple REST API.

Base URL

https://dnschkr.com/api/v1/

Requirements

  • A subscription that covers the endpoints you want to call. A general plan (pricing) covers every endpoint, including IP Intelligence. An IP Intelligence plan has a free tier (1,000 IP lookups/day) and covers only the IP Intelligence endpoint.
  • API key generated from your dashboard

Platform guides

Drop-in integrations for common stacks.

  • WordPress integration guide — ten production-ready PHP recipes built on a single mu-plugin helper: wp-login.php brute-force defense, WooCommerce checkout fraud scoring, EU-only GDPR banner, hosting-ASN throttling, and bulk WP-CLI enrichment.

Authentication

All API requests require a Bearer token. Generate API keys from your dashboard.

cURL

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/whois?domain=example.com"

JavaScript

const res = await fetch('https://dnschkr.com/api/v1/whois?domain=example.com', {
  headers: { 'Authorization': 'Bearer dk_live_...',
    'Accept': 'application/json'}
});
const { data, meta } = await res.json();

Python

import requests

r = requests.get('https://dnschkr.com/api/v1/whois',
    params={'domain': 'example.com'},
    headers={'Authorization': 'Bearer dk_live_...',
    'Accept': 'application/json'})
data = r.json()

Note: API keys are shown once at creation. Store them securely. If lost, revoke and create a new key from your dashboard.

Response Format

All successful responses follow a standard envelope with data and meta fields. Properties use camelCase. Dates are ISO 8601 format. Paginated endpoints include a nextCursor in meta.

{
  "data": { ... },
  "meta": {
    "requestId": "550e8400-e29b-41d4-a716-446655440000",
    "timestamp": "2026-03-03T12:00:00.000Z",
    "credits": { "used": 1, "remaining": 49 },
    "nextCursor": "..."  // only on paginated endpoints
  }
}

The credits object contains used (credits consumed by this request) and remaining (credits left in current period). Free endpoints return used: 0.

Response Headers

HeaderDescription
X-Credits-UsedNumber of credits consumed by this request
X-Credits-RemainingCredits remaining in current period
X-RateLimit-LimitMaximum requests allowed per day
X-RateLimit-RemainingRequests remaining today
X-RateLimit-ResetUnix timestamp when rate limit resets (midnight UTC)

Error Codes

Error responses include a structured error object with machine-readable code, human-readable message, and HTTP status.

{
  "error": {
    "code": "MISSING_PARAMETER",
    "message": "Required parameter 'domain' is missing",
    "status": 400
  },
  "meta": {
    "requestId": "550e8400-e29b-41d4-a716-446655440000",
    "timestamp": "2026-03-03T12:00:00.000Z"
  }
}
CodeStatusDescription
MISSING_PARAMETER400Required parameter not provided
INVALID_PARAMETER400Parameter value is invalid
UNAUTHORIZED401Missing or invalid API key
FORBIDDEN403API access requires a paid plan
NOT_FOUND404Resource not found
INSUFFICIENT_CREDITS402Not enough credits for this request
RATE_LIMITED429Daily request limit exceeded
INTERNAL_ERROR500Internal server error
UPSTREAM_ERROR502Backend service returned an error or is unavailable
SERVICE_UNAVAILABLE503Credit system temporarily unavailable
TIMEOUT504Backend service timed out

Rate Limits

Per-key request limits depend on the active subscription. Two product lines are billed separately:

ProductPlanQuota
General API
See pricing
Starter100 requests/day
Plus100 requests/day
Pro1,000 requests/day
IP Intelligence
See pricing
Free1,000 IP lookups/day
Indie50,000 IP lookups/month
Growth300,000 IP lookups/month
Scale2,000,000 IP lookups/month

Rate limit status is included in response headers:

  • X-RateLimit-Limit - Maximum requests per day
  • X-RateLimit-Remaining - Requests remaining today
  • X-RateLimit-Reset - Unix timestamp of next reset (midnight UTC)

When rate limited, the response includes a Retry-After header with the number of seconds until the limit resets.

Credits

API calls consume credits from the active subscription. Credit cost varies by endpoint complexity. Credit balance is included in every response body and headers. Some endpoints (MX, SPF, DKIM, DMARC, Robots.txt) are free and consume no credits.

Cross-product credit rules

  • A general plan covers every endpoint, including IP Intelligence (the underlying tool at /ip-address-lookup is the same service).
  • An IP Intelligence plan covers only the IP Intelligence endpoint. Its credits do not stack onto DNS Inspector, WHOIS, port scan, or other endpoints.
  • Customers holding both a general plan and an IP Intelligence plan see a combined IP Intelligence quota; other endpoints draw only from the general plan's pool.
EndpointCredit Cost
WHOIS Lookup1 credit
Domain Age1 credit
Domain Expiry1 credit
Reverse WHOIS3 credits
Expiring Domains3 credits
Bulk WHOIS (per request)5 credits
DNS Lookup1 credit
IP Intelligence1 credit
MX Records0 (free) credits
SPF Check0 (free) credits
DKIM Check0 (free) credits
DMARC Check0 (free) credits
Port Scan2 credits
Security Headers1 credit
Robots.txt Check0 (free) credits
Reverse NS Lookup1 credit

View your current credit balance and usage history in your dashboard.

GET/api/v1/whois1 credit

Retrieve WHOIS/RDAP registration data for a domain including registrar, dates, nameservers, and status codes.

Try it free at the WHOIS Lookup tool to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
domainstringRequiredDomain name to look up (e.g. example.com)

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/whois?domain=example.com"

Example Response

{
  "data": {
    "domain": "example.com",
    "registrar": "RESERVED-Internet Assigned Numbers Authority",
    "createdDate": "1995-08-14T04:00:00Z",
    "expiresDate": "2026-08-13T04:00:00Z",
    "updatedDate": "2024-08-14T07:01:38Z",
    "nameservers": ["a.iana-servers.net", "b.iana-servers.net"],
    "statusCodes": ["client delete prohibited", "server update prohibited"],
    "domainAge": { "years": 30, "months": 6, "days": 17, "totalDays": 11159 },
    "rawRdap": { "..." : "full RDAP response object" }
  },
  "meta": {
    "requestId": "550e8400-e29b-41d4-a716-446655440000",
    "timestamp": "2026-03-03T12:00:00.000Z",
    "credits": { "used": 1, "remaining": 49 }
  }
}
GET/api/v1/whois/age1 credit

Get the age of a domain computed from its WHOIS creation date.

Try it free at the Domain Age Checker to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
domainstringRequiredDomain name to check (e.g. example.com)

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/whois/age?domain=example.com"

Example Response

{
  "data": {
    "domain": "example.com",
    "createdDate": "1995-08-14T04:00:00Z",
    "age": { "years": 30, "months": 6, "days": 17, "totalDays": 11159 },
    "registrar": "RESERVED-Internet Assigned Numbers Authority"
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 1, "remaining": 48 } }
}
GET/api/v1/whois/expiry1 credit

Check when a domain expires and how many days remain.

Try it free at the Domain Expiry Checker to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
domainstringRequiredDomain name to check (e.g. example.com)

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/whois/expiry?domain=example.com"

Example Response

{
  "data": {
    "domain": "example.com",
    "expiresDate": "2026-08-13T04:00:00Z",
    "daysRemaining": 163,
    "status": "active",
    "registrar": "RESERVED-Internet Assigned Numbers Authority"
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 1, "remaining": 47 } }
}
GET/api/v1/whois/reverse2 credits

Search domains by registrar, nameserver provider, TLD, or creation date range. At least one filter parameter is required.

Try it free at the Reverse WHOIS tool to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
registrarstringOptionalFilter by registrar name (partial match)
ns_providerstringOptionalFilter by nameserver provider
tldstringOptionalFilter by TLD (e.g. com, net)
created_afterstringOptionalISO 8601 date, domains created after
created_beforestringOptionalISO 8601 date, domains created before
cursorstringOptionalPagination cursor from previous response
limitnumberOptionalResults per page (default 25, max 100)

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/whois/reverse?registrar=GoDaddy&tld=com&limit=10"

Example Response

{
  "data": [
    {
      "domain": "example-domain.com",
      "registrar": "GoDaddy.com, LLC",
      "createdDate": "2020-01-15T00:00:00Z",
      "expiresDate": "2026-01-15T00:00:00Z",
      "nameservers": ["ns1.example.com"]
    }
  ],
  "meta": {
    "requestId": "...",
    "timestamp": "...",
    "credits": { "used": 3, "remaining": 44 },
    "nextCursor": "eyJzZWFyY2hfYWZ0ZXIiOlsiMjAyMC..."
  }
}
GET/api/v1/whois/expiring2 credits

Find domains expiring within a specified number of days.

Try it free at the Expiring Domains feed to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
daysnumberRequiredDays until expiry (1-365)
tldstringOptionalFilter by TLD (e.g. com, net)
keywordstringOptionalSearch keyword in domain name (e.g. solar, crypto)
match_typestringOptionalKeyword match mode: starts_with (default), contains, or ends_with
min_lengthnumberOptionalMinimum domain label length (1-63, per RFC 1035)
max_lengthnumberOptionalMaximum domain label length (1-63, per RFC 1035)
min_agenumberOptionalMinimum domain age in years
cursorstringOptionalPagination cursor from previous response
limitnumberOptionalResults per page (default 100, max 100)

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/whois/expiring?days=30&tld=com&keyword=solar&match_type=starts_with&limit=25"

Example Response

{
  "data": [
    {
      "domain": "expiring-soon.com",
      "expiresDate": "2026-03-28T00:00:00Z",
      "daysRemaining": 25,
      "registrar": "Namecheap, Inc.",
      "createdDate": "2015-03-28T00:00:00Z"
    }
  ],
  "meta": {
    "requestId": "...",
    "timestamp": "...",
    "credits": { "used": 3, "remaining": 41 },
    "nextCursor": "..."
  }
}
POST/api/v1/whois/bulk3 credits

Look up WHOIS data for multiple domains in a single request. Maximum 100 domains per request.

Try it free at the WHOIS Lookup tool (single-domain) to sanity-check the response before wiring code.

Body Parameters

NameTypeRequiredDescription
domainsstring[]RequiredArray of domain names (max 100)

Example Request

curl -X POST -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  -H "Content-Type: application/json" \
  -d '{"domains":["example.com","example.net"]}' \
  "https://dnschkr.com/api/v1/whois/bulk"

Example Response

{
  "data": [
    {
      "domain": "example.com",
      "registrar": "RESERVED-Internet Assigned Numbers Authority",
      "createdDate": "1995-08-14T04:00:00Z",
      "expiresDate": "2026-08-13T04:00:00Z",
      "nameservers": ["a.iana-servers.net", "b.iana-servers.net"]
    },
    {
      "domain": "example.net",
      "registrar": "RESERVED-Internet Assigned Numbers Authority",
      "createdDate": "1995-08-14T04:00:00Z",
      "expiresDate": "2026-08-13T04:00:00Z",
      "nameservers": ["a.iana-servers.net", "b.iana-servers.net"]
    }
  ],
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 5, "remaining": 36 } }
}
GET/api/v1/dns1 credit

Query DNS records for a domain. Supports all major record types.

Try it free at DNS Inspector to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
domainstringRequiredDomain name to query
typestringOptionalRecord type: A, AAAA, MX, NS, TXT, CNAME, SOA, PTR, SRV, CAA (default: A)

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/dns?domain=example.com&type=MX"

Example Response

{
  "data": {
    "domain": "example.com",
    "type": "MX",
    "records": [
      { "priority": 10, "value": "mail.example.com", "ttl": 3600 }
    ]
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 1, "remaining": 35 } }
}
GET/api/v1/dns-inspector1 credit

Run a comprehensive DNS health inspection on a domain. Returns 40+ tests across 11 categories including nameservers, SOA, A/AAAA, MX, security (DNSSEC, zone transfer), TXT (SPF), WWW, and performance.

Try it free at DNS Inspector to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
domainstringRequiredDomain name to inspect (e.g. example.com)

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/dns-inspector?domain=example.com"

Example Response

{
  "data": {
    "domain": "example.com",
    "dns": {
      "domain": "example.com",
      "categories": {
        "parent": [
          { "test": "Authoritative Nameservers", "status": { "text": "Info" }, "info": { "providers": [...] } },
          { "test": "TLD Delegation Check", "status": { "text": "Pass" } }
        ],
        "ns": [
          { "test": "Nameserver Records from Zone", "status": { "text": "Info" } },
          { "test": "Open Recursive Queries", "status": { "text": "Pass" } },
          { "test": "NS Record TTL", "status": { "text": "Pass" } }
        ],
        "soa": [
          { "test": "SOA record", "status": { "text": "Info" } },
          { "test": "SOA Serial Consistency", "status": { "text": "Pass" } }
        ],
        "a": [
          { "test": "A Record Configuration", "status": { "text": "Info" } },
          { "test": "A Record TTL", "status": { "text": "Pass" } }
        ],
        "aaaa": [
          { "test": "IPv6 Configuration", "status": { "text": "Info" } }
        ],
        "mx": [
          { "test": "Mail Server Configuration", "status": { "text": "Info" } },
          { "test": "Mail Server Consistency", "status": { "text": "Pass" } }
        ],
        "security": [
          { "test": "DNSSEC", "status": { "text": "Info" } },
          { "test": "Zone Transfer", "status": { "text": "Info" } }
        ],
        "txt": [
          { "test": "TXT Records", "status": { "text": "Info" } },
          { "test": "SPF Record", "status": { "text": "Pass" } }
        ],
        "www": [
          { "test": "WWW Configuration", "status": { "text": "Pass" } }
        ],
        "performance": [
          { "test": "Analysis Performance", "status": { "text": "Info" } }
        ]
      },
      "raw": { "A": [...], "AAAA": [...], "MX": [...], "NS": [...], "TXT": [...], "SOA": [...] }
    }
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 1, "remaining": 34 } }
}
GET/api/v1/ip1 credit

Full IP intelligence for a single IPv4 or IPv6 address. Returns geolocation, ASN, threat detection, network WHOIS, a classification block (residential / hosting / VPN / Tor / proxy / etc.), a recommendation block with a severity score and suggested action, and an optional named-service block when the IP belongs to a known CDN, cloud platform, or search-engine crawler.

Try it free at the free IP geolocation tool to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
addressstringRequiredIPv4 or IPv6 address to look up
fallbackstringOptionalSet to "full" to opt into a Content API fallback for WHOIS enrichment on cache miss. Slower (adds up to 2 s) but returns more complete network registration data when the edge cache has no record.
rdnsstringOptionalSet to "false" to skip the reverse DNS lookup and return immediately without waiting for PTR resolution. Useful when latency matters more than rDNS data. When omitted, rDNS is always attempted.

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/ip?address=8.8.8.8"

Example Response

{
  "data": {
    "ip": "8.8.8.8",
    "type": "IPv4",
    "success": true,
    "geo": {
      "continent": "North America",
      "continentCode": "NA",
      "country": "United States",
      "countryCode": "US",
      "isEu": false,
      "region": "California",
      "regionCode": "CA",
      "city": "Mountain View",
      "postal": "94043",
      "latitude": 37.4056,
      "longitude": -122.0775,
      "accuracyRadiusKm": 1000,
      "flagEmoji": "🇺🇸",
      "capital": "Washington D.C.",
      "callingCode": "+1",
      "currency": "USD"
    },
    "network": {
      "asn": 15169,
      "organization": "GOOGLE",
      "isp": "Google LLC",
      "networkCidr": "8.8.8.0/24",
      "rir": "ARIN",
      "reverseDns": "dns.google",
      "reverseDnsValid": true
    },
    "timezone": {
      "id": "America/Los_Angeles",
      "abbreviation": "PST",
      "utcOffset": "-08:00",
      "currentTime": "2026-04-27T16:12:34-08:00",
      "isDst": false
    },
    "security": {
      "isTor": false,
      "isVpn": false,
      "isProxy": false,
      "isDatacenter": true,
      "isRelay": false,
      "isBogon": false,
      "threatScore": 0,
      "threatLevel": "none",
      "detectionSources": [],
      "detectedServices": ["google-public-dns"],
      "ipType": "datacenter"
    },
    "abuse": {
      "networkName": "GOGL",
      "description": "Google LLC",
      "country": "US"
    },
    "classification": {
      "primaryType": "hosting",
      "isResidential": false,
      "isMobile": false,
      "isBusiness": false,
      "isHosting": true,
      "isVpn": false,
      "isTor": false,
      "isProxy": false,
      "isResidentialProxy": false,
      "isCloudGaming": false,
      "isPrivacyRelay": false,
      "isBogon": false
    },
    "recommendation": {
      "severity": 0,
      "action": "allow",
      "score": 0,
      "confidence": "high",
      "reasons": [],
      "summary": "Known Google infrastructure. No threat signals detected."
    },
    "service": {
      "name": "Google Public DNS",
      "category": "public-dns"
    },
    "whois": {
      "handle": "NET-8-8-8-0-2",
      "rir": "ARIN",
      "networkName": "LVLT-GOGL-8-8-8",
      "startAddress": "8.8.8.0",
      "endAddress": "8.8.8.255",
      "cidrList": ["8.8.8.0/24"],
      "org": { "name": "Google LLC", "id": "GOGL", "address": "1600 Amphitheatre Parkway, Mountain View, CA 94043, US" },
      "abuse": { "email": "[email protected]", "phone": "+1-650-253-0000" },
      "technical": { "email": "[email protected]", "phone": null },
      "dates": {
        "registration": "2014-03-14T00:00:00Z",
        "lastChanged": "2014-03-14T00:00:00Z",
        "lastQueried": "2026-04-27T00:00:00Z"
      },
      "status": ["active"],
      "contentHash": "abc123",
      "contacts": [
        {
          "category": "general_abuse",
          "displayName": "Abuse",
          "tier": "standard",
          "source": "entity",
          "role": "abuse",
          "name": "Google LLC",
          "org": "Google LLC",
          "emails": ["[email protected]"],
          "phones": ["+1-650-253-0000"],
          "address": null,
          "handle": "ABUSE5250-ARIN",
          "remarks": null
        }
      ]
    },
    "whoisStatus": "available",
    "meta": {
      "dataFreshness": {
        "geoliteCity": "2026-04-15",
        "geoliteAsn": "2026-04-15",
        "torNodes": "2026-04-27",
        "cloudRanges": "2026-04-20",
        "proxyLists": "2026-04-22"
      },
      "queryTimeMs": 142,
      "cached": false
    }
  },
  "meta": {
    "requestId": "550e8400-e29b-41d4-a716-446655440000",
    "timestamp": "2026-04-27T00:12:34.000Z",
    "credits": { "used": 1, "remaining": 49, "dailyLimit": 50, "isAuthenticated": true }
  }
}

// Notes:
// • whoisStatus: "available"         — WHOIS data found and returned in whois block
// • whoisStatus: "not_in_data"       — IP not present in the RDAP index; whois is null
// • whoisStatus: "block_no_handle"   — Block found but has no ARIN/RIPE/APNIC handle; whois is null
// • whoisStatus: "ip_unknown"        — IP version not recognisable (rare); whois is null
// • whoisStatus: "skipped"           — Content API not configured; whois is null
//
// • service is null for IPs that don't belong to a named service
// • network.reverseDns is null and network.reverseDnsValid is false when PTR lookup fails
//   or when rdns=false is passed (network.rdnsSkipped will be true in that case)
// • recommendation.severity: 0=allow, 1=review, 2=block
// • recommendation.confidence: "low" | "medium" | "high"
GET/api/v1/mxFree

Look up MX (Mail Exchange) records for a domain with priority and provider detection.

Try it free at the MX Record Lookup tool to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
domainstringRequiredDomain name to check

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/mx?domain=example.com"

Example Response

{
  "data": {
    "domain": "example.com",
    "records": [
      { "priority": 10, "exchange": "mail.example.com", "ttl": 3600 }
    ]
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 0, "remaining": 49 } }
}
GET/api/v1/spfFree

Validate and parse the SPF (Sender Policy Framework) record for a domain. Detects DNS lookup count, void lookups (RFC 7208 §4.6.4), include chain resolution, and policy analysis.

Try it free at the SPF Record Checker to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
domainstringRequiredDomain name to check

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/spf?domain=example.com"

Example Response

{
  "data": {
    "domain": "example.com",
    "record": "v=spf1 include:_spf.google.com -all",
    "valid": true,
    "dnsLookups": 4,
    "dnsLookupLimit": 10,
    "voidLookups": 0,
    "voidLookupLimit": 2,
    "voidLookupDetails": [],
    "mechanisms": [
      { "qualifier": "+", "type": "include", "value": "_spf.google.com" },
      { "qualifier": "-", "type": "all", "value": "" }
    ],
    "includeTree": [{ "domain": "example.com", "lookups": 4, "children": [...], "voidLookup": false }],
    "qualifier": "-all"
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 0, "remaining": 49 } }
}
GET/api/v1/dkimFree

Look up and validate the DKIM (DomainKeys Identified Mail) record for a domain.

Try it free at the DKIM Record Checker to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
domainstringRequiredDomain name to check
selectorstringOptionalDKIM selector (default: "default")

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/dkim?domain=example.com&selector=google"

Example Response

{
  "data": {
    "domain": "example.com",
    "selector": "google",
    "record": "v=DKIM1; k=rsa; p=MIIBIjANBg...",
    "valid": true,
    "keyType": "rsa",
    "keyLength": 2048
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 0, "remaining": 49 } }
}
GET/api/v1/dmarcFree

Look up and parse the DMARC (Domain-based Message Authentication) record for a domain. Verifies external reporting authorization per RFC 7489 §7.1.

Try it free at the DMARC Record Checker to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
domainstringRequiredDomain name to check

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/dmarc?domain=example.com"

Example Response

{
  "data": {
    "domain": "example.com",
    "record": "v=DMARC1; p=reject; rua=mailto:[email protected]",
    "valid": false,
    "policy": "reject",
    "subdomainPolicy": null,
    "alignment": { "spf": "relaxed", "dkim": "relaxed" },
    "reporting": {
      "aggregate": ["mailto:[email protected]"],
      "forensic": [],
      "interval": 86400,
      "format": "afrf",
      "failureOptions": "0"
    },
    "externalReporting": [{
      "uri": "mailto:[email protected]",
      "destinationDomain": "thirdparty.com",
      "isExternal": true,
      "authorized": false,
      "authorizationRecord": null
    }],
    "adoptionLevel": "enforced",
    "percentage": 100
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 0, "remaining": 49 } }
}
POST/api/v1/port-scan1 credit

Scan TCP ports on a target host. Maximum 20 ports per request.

Try it free at the Port Scanner to sanity-check the response before wiring code.

Body Parameters

NameTypeRequiredDescription
targetstringRequiredHostname or IP address to scan
portsnumber[]RequiredArray of port numbers (max 20)

Example Request

curl -X POST -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  -H "Content-Type: application/json" \
  -d '{"target":"example.com","ports":[80,443,22]}' \
  "https://dnschkr.com/api/v1/port-scan"

Example Response

{
  "data": {
    "target": "example.com",
    "results": [
      { "port": 80, "status": "open", "service": "HTTP" },
      { "port": 443, "status": "open", "service": "HTTPS" },
      { "port": 22, "status": "closed", "service": "SSH" }
    ]
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 2, "remaining": 33 } }
}
GET/api/v1/security-headers1 credit

Analyze HTTP security headers for a URL and get a security grade.

Try it free at the HTTP Security Headers tool to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
urlstringRequiredFull URL to analyze (e.g. https://example.com)

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/security-headers?url=https://example.com"

Example Response

{
  "data": {
    "url": "https://example.com",
    "grade": "B",
    "headers": {
      "strictTransportSecurity": { "present": true, "value": "max-age=31536000" },
      "contentSecurityPolicy": { "present": false, "value": null },
      "xFrameOptions": { "present": true, "value": "DENY" },
      "xContentTypeOptions": { "present": true, "value": "nosniff" }
    },
    "recommendations": ["Add Content-Security-Policy header"]
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 1, "remaining": 32 } }
}
GET/api/v1/robotsFree

Fetch, validate, and parse a domain's robots.txt file. Returns the raw content, HTTP status, content type, file size, validation warnings, and whether the file is valid. Use the parsed data to build crawl access matrices, security analysis, or SEO audits.

Try it free at the Robots.txt Checker to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
domainstringRequiredDomain name to check (e.g. example.com)

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/robots?domain=example.com"

Example Response

{
  "data": {
    "data": {
      "domain": "example.com",
      "url": "https://example.com/robots.txt",
      "statusCode": 200,
      "headers": { "content-type": "text/plain", "content-length": "142" },
      "content": "User-agent: *\nDisallow: /admin\nAllow: /\n\nSitemap: https://example.com/sitemap.xml",
      "contentType": "text/plain",
      "isValid": true,
      "isHtml": false,
      "warnings": [],
      "byteLength": 142,
      "error": null
    },
    "meta": {
      "cached": false,
      "fetchedAt": "2026-03-07T12:00:00.000Z",
      "duration": 245
    }
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 0, "remaining": 49 } }
}
GET/api/v1/redirect-checkFree

Trace the full HTTP redirect chain for any URL. Returns every hop in the chain with status codes, response headers, timing, resolved IP, and SSL/TLS certificate details per hop. Use this to audit redirect configurations, detect redirect loops, find broken SSL certificates, or analyze SEO redirect chains.

Try it free at the Redirect Checker to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
urlstringRequiredURL to trace (e.g. http://example.com or example.com). If no protocol is specified, http:// is assumed.
userAgentstringOptionalCustom User-Agent string. Use to test how different crawlers (Googlebot, Bingbot) experience the redirect chain.

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/redirect-check?url=http://example.com"

Example Response

{
  "data": {
    "startUrl": "http://example.com",
    "finalUrl": "https://www.example.com/",
    "hops": [
      {
        "hop": 1,
        "url": "http://example.com",
        "statusCode": 301,
        "statusMessage": "Moved Permanently",
        "headers": { "location": "https://example.com/", "server": "nginx" },
        "timing": 120,
        "ip": "93.184.216.34"
      },
      {
        "hop": 2,
        "url": "https://example.com/",
        "statusCode": 301,
        "statusMessage": "Moved Permanently",
        "headers": { "location": "https://www.example.com/" },
        "timing": 95,
        "ip": "93.184.216.34",
        "tls": {
          "protocol": "TLSv1.3",
          "cipher": "TLS_AES_256_GCM_SHA384",
          "valid": true,
          "subject": "www.example.org",
          "issuer": "DigiCert Global G2 TLS RSA SHA256 2020 CA1",
          "validFrom": "2024-01-30T00:00:00.000Z",
          "validTo": "2025-03-01T23:59:59.000Z",
          "daysRemaining": 182,
          "selfSigned": false
        }
      },
      {
        "hop": 3,
        "url": "https://www.example.com/",
        "statusCode": 200,
        "statusMessage": "OK",
        "headers": { "content-type": "text/html" },
        "timing": 88,
        "ip": "93.184.216.34",
        "tls": {
          "protocol": "TLSv1.3",
          "cipher": "TLS_AES_256_GCM_SHA384",
          "valid": true,
          "subject": "www.example.org",
          "issuer": "DigiCert Global G2 TLS RSA SHA256 2020 CA1",
          "daysRemaining": 182,
          "selfSigned": false
        }
      }
    ],
    "totalHops": 3,
    "totalTime": 303,
    "isRedirect": true,
    "hasLoop": false,
    "reachedMaxHops": false
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 0, "remaining": 49 } }
}
GET/api/v1/seo-auditFree

Run a comprehensive on-page SEO audit for any URL. Analyzes meta tags, headings, images, links, structured data, and more.

Try it free at the On-Page SEO Auditor to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
urlstringRequiredURL to audit (e.g. https://example.com). If no protocol, https:// is assumed.

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/seo-audit?url=https://example.com"

Example Response

{
  "data": {
    "url": "https://example.com",
    "statusCode": 200,
    "title": "Example Domain",
    "meta": {
      "description": "This domain is for use in illustrative examples.",
      "robots": "index, follow",
      "viewport": "width=device-width, initial-scale=1"
    },
    "headings": {
      "h1": ["Example Domain"],
      "h2": [],
      "h3": []
    },
    "links": { "internal": 0, "external": 1, "nofollow": 0 },
    "images": { "total": 0, "withoutAlt": 0 },
    "structuredData": [],
    "performance": { "loadTime": 245, "contentLength": 1256 }
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 0, "remaining": 49 } }
}
GET/api/v1/reverse-ns1 credit

Find all domains using a given nameserver. Returns domain names sorted alphabetically with first/last seen dates. Pro plan required.

Try it free at the Reverse Nameserver Lookup tool to sanity-check the response before wiring code.

Query Parameters

NameTypeRequiredDescription
nsstringRequiredNameserver hostname (e.g. ns1.google.com)
limitnumberOptionalMax domains to return (default: 100, max: 1000)
offsetnumberOptionalPagination offset (default: 0)

Example Request

curl -H "Authorization: Bearer dk_live_..." -H "Accept: application/json" \
  "https://dnschkr.com/api/v1/reverse-ns?ns=ns1.google.com&limit=10"

Example Response

{
  "data": {
    "nameserver": "ns1.google.com",
    "total": 11677,
    "limit": 10,
    "offset": 0,
    "domains": [
      { "domain": "0---0.com", "tld": "com", "firstSeen": "2026-04-10", "lastSeen": "2026-04-10" }
    ]
  },
  "meta": { "requestId": "...", "timestamp": "...", "credits": { "used": 1, "remaining": 48 } }
}

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