GET/api/v2/reverse-dns

Reverse DNS API

An IP address's PTR names, whether they point back (FCrDNS), who runs its reverse zone, and the mail providers' PTR rules.

20 calls a minute per IP
Same engine as the Reverse DNS Lookup tool

200 OKRecorded 2026-10-25. Send it to run the request live.

{
  "query": {
    "ip": "8.8.8.8"
  },
  "ip": "8.8.8.8",
  "reverseName": "8.8.8.8.in-addr.arpa",
  "specialUse": null,
  "verdict": "confirmed",
  "role": "resolver",
  "ptr": [
    {
      "name": "dns.google",
      "ttl": 86400,
      "forwardConfirmed": true,
      "ipv4": [
        "8.8.8.8",
        "8.8.4.4"
      ],
      "ipv6": [
        "2001:4860:4860::8844",
        "2001:4860:4860::8888"
      ],
      "kind": "named"
    }
  ],
  "forwardConfirmed": true,
  "answer": {
    "source": "authoritative",
    "server": "ns2.google.com",
    "ip": "216.239.34.10",
    "viaCloudflare": false,
    "status": "ok",
    "rcode": "NOERROR",
    "authoritative": true,
    "negativeTtl": null,
    "cnameChain": []
  },
  "zone": {
    "name": "8.8.8.in-addr.arpa",
    "operator": {
      "kind": "holder",
      "id": "google",
      "name": "Google"
    }
  },
  "delegation": [
    {
      "zone": ".",
      "server": "b.root-servers.net",
      "ip": "170.247.170.2",
      "outcome": "referral",
      "operator": {
        "kind": "root",
        "id": "root",
        "name": "Root"
      },
      "nsTtl": 172800,
      "leg": 1
    },
    {
      "zone": "in-addr.arpa",
      "server": "f.in-addr-servers.arpa",
      "ip": "193.0.9.1",
      "outcome": "referral",
      "operator": {
        "kind": "iana",
        "id": "iana",
        "name": "IANA"
      },
      "nsTtl": 86400,
      "leg": 1
    },
    {
      "zone": "8.in-addr.arpa",
      "server": "arin.authdns.ripe.net",
      "ip": "193.0.9.10",
      "outcome": "referral",
      "operator": {
        "kind": "rir",
        "id": "arin",
        "name": "ARIN"
      },
      "nsTtl": 86400,
      "leg": 1
    },
    {
      "zone": "8.8.8.in-addr.arpa",
      "server": "ns2.google.com",
      "ip": "216.239.34.10",
      "outcome": "authoritative",
      "operator": {
        "kind": "holder",
        "id": "google",
        "name": "Google"
      },
      "nsTtl": null,
      "leg": 1
    }
  ],
  "network": {
    "asn": 15169,
    "name": "Google",
    "asName": "GOOGLE - Google LLC, US",
    "prefix": "8.8.8.0/24",
    "country": "US",
    "registry": "arin",
    "allocated": "2023-12-28"
  },
  "mail": {
    "name": "dns.google",
    "pass": 3,
    "providers": [
      {
        "id": "gmail",
        "ptr": "pass",
        "fcrdns": "pass",
        "notGeneric": "not_required",
        "pass": true,
        "unknown": false
      },
      {
        "id": "yahoo",
        "ptr": "pass",
        "fcrdns": "pass",
        "notGeneric": "pass",
        "pass": true,
        "unknown": false
      },
      {
        "id": "outlook",
        "ptr": "pass",
        "fcrdns": "not_required",
        "notGeneric": "pass",
        "pass": true,
        "unknown": false
      }
    ]
  },
  "crawler": null,
  "ptrProvider": null,
  "copies": [
    {
      "source": "google",
      "status": "ok",
      "names": [
        "dns.google"
      ],
      "ttl": 1040,
      "tookMs": 33
    },
    {
      "source": "cloudflare",
      "status": "ok",
      "names": [
        "dns.google"
      ],
      "ttl": 79471,
      "tookMs": 1
    }
  ],
  "issues": [],
  "tookMs": 2314
}

Jump to a section

How it works

Walks the reverse zone down from a root server (IANA, then the Regional Internet Registry, then the block's holder), asks the zone's own nameservers for the PTR beside Google's and Cloudflare's copies, and follows RFC 2317 classless delegations. Every PTR name is looked up forward: a name that resolves back to the address is forward-confirmed (FCrDNS); a forward lookup that didn't finish is unknown, never "doesn't point back".

mail reads the answer against Gmail's, Yahoo Mail's and Outlook.com's published PTR rules, and generic names (the address's digits, ISP pool words, a cloud's default) are told apart from a name of your own. Crawler names (Googlebot, Bingbot, Applebot…) are verified the way their operators document: the PTR's domain plus the forward lookup, or the published IP lists.

Private and other special-use addresses have no public reverse DNS and are refused (422). The address itself is never connected to; the IP to Hostname page's certificate and HTTP probes aren't part of the API.

Answers kept: Kept for the PTR record's TTL, 30 seconds to 5 minutes (30 seconds when a part failed), shared with the Reverse DNS page. A kept answer carries an `Age` header, and the resolvers' TTLs are counted down.

Query parameters

ipstringrequired
An IPv4 or IPv6 address in any usual notation, or its in-addr.arpa / ip6.arpa name. An IPv4-mapped or NAT64 address is looked up as the IPv4 address it carries.

Response fields

200 with this JSON object, plus tookMs, and incomplete with warnings when a source failed. Fields marked optional appear only when they apply.

queryobjectalways
What was looked up, normalised (lower case, no trailing dot, IDNs as Punycode).
- ipstringalways
  The address as given, normalised (IPv6 compressed, RFC 5952).
ipstringalways
The address looked up: the one given, or the IPv4 address inside an IPv4-mapped or NAT64 one.
reverseNamestring or nullalways
Its reverse name: in-addr.arpa, or all 32 nibbles under ip6.arpa.
specialUseobject or nullalways
The IANA special-purpose block it is in, when it is in one that still has public reverse DNS.
- cidrstringalways
  The block.
- namestringalways
  Its name in IANA's registry.
- rfcstringalways
  The RFC that reserves it.
verdictstringalways
confirmed (a PTR that points back), generic (it points back, but it is the provider's generic name), not_confirmed (no PTR name resolves back), unverified (a forward lookup didn't finish), crawler (a verified crawler), fake_crawler, google_cloud, no_ptr, broken (the reverse zone answers SERVFAIL or REFUSED), no_answer, unreadable or special_use.
one of "confirmed", "generic", "not_confirmed", "unverified", "crawler", "fake_crawler", "google_cloud", "no_ptr", "broken", "no_answer", "unreadable", "special_use"
rolestringalways
What the address is, from its names and network: a public resolver, a crawler (or crawler_fake, crawler_unverified), google_cloud, mail, cloud (a cloud's default name), cdn, an ISP pool, as112, infra, named, generic or none.
one of "resolver", "crawler", "crawler_fake", "crawler_unverified", "google_cloud", "mail", "cloud", "cdn", "pool", "as112", "infra", "named", "generic", "none"
ptrarray of objectsalways
The PTR records of the answer that counts.
Show 6 fields
- namestringalways
  The name, lower case.
- ttlintegeralways
  The record's TTL, in seconds.
- forwardConfirmedboolean or nullalways
  The name resolves back to the address; null when the forward lookup didn't finish or wasn't made (past the first 10 names).
- ipv4array of stringsalways
  The name's A records.
- ipv6array of stringsalways
  The name's AAAA records.
- kindstringalways
  named (a name of its own), generic (a provider's default), crawler (a crawler's documented domain) or infra (network infrastructure).
  one of "named", "generic", "crawler", "infra"
forwardConfirmedboolean or nullalways
At least one PTR name points back (FCrDNS passes); false when every name was checked and none does; null when it couldn't be settled or there is no PTR.
answerobject or nullalways
The PTR answer that counts: the reverse zone's own, unless it couldn't be had; then a resolver's.
Show 9 fields
- sourcestringalways
  Who answered: authoritative (the zone's own nameserver, the fresh truth), google (Google Public DNS's cached copy) or cloudflare (Cloudflare 1.1.1.1's).
  one of "authoritative", "google", "cloudflare"
- serverstring or nullalways
  The server that answered.
- ipstring or nullalways
  Its address.
- viaCloudflarebooleanalways
  The reverse zone is on Cloudflare's nameservers: this is 1.1.1.1's answer.
- statusstringalways
  The answer: ok (records came back), nodata (the name exists without them), nxdomain (no such name), servfail, refused, timeout, error or unreadable (an answer our decoder refuses).
  one of "ok", "nodata", "nxdomain", "servfail", "refused", "timeout", "error", "unreadable"
- rcodestring or nullalways
  The response code.
- authoritativeboolean or nullalways
  The AA flag.
- negativeTtlinteger or nullalways
  For no PTR: how long the miss is cached, in seconds.
- cnameChainarray of objectsalways
  The CNAMEs the answer followed, in order.
  Show 3 fields
  - namestringalways
    The alias.
  - targetstringalways
    The name it points to.
  - ttlintegeralways
    The record's TTL, in seconds.
zoneobject or nullalways
The reverse zone that answered and who runs it.
- namestringalways
  The zone, e.g. 8.8.8.in-addr.arpa.
- operatorobject or nullalways
  Who runs it: the root, IANA, a Regional Internet Registry, or the address block's holder.
  Show 3 fields
  - kindstringalways
    root, iana, rir or holder.
    one of "root", "iana", "rir", "holder"
  - idstringalways
    A stable id: iana, arin, ripe, apnic, lacnic, afrinic, or the holder's.
  - namestringalways
    Its name.
delegationarray of objectsalways
The path down from the root to the reverse zone.
Show 7 fields
- zonestringalways
  The zone this server answers for (. for a root server).
- serverstringalways
  The server asked.
- ipstring or nullalways
  Its address.
- outcomestringalways
  referral (sent us one level down), authoritative, nxdomain, blocked (on Cloudflare's network), ipv6 (IPv6-only servers), lame, timeout or error.
  one of "referral", "authoritative", "nxdomain", "blocked", "ipv6", "lame", "timeout", "error"
- operatorobject or nullalways
  Who runs it: the root, IANA, a Regional Internet Registry, or the address block's holder.
  Show 3 fields
  - kindstringalways
    root, iana, rir or holder.
    one of "root", "iana", "rir", "holder"
  - idstringalways
    A stable id: iana, arin, ripe, apnic, lacnic, afrinic, or the holder's.
  - namestringalways
    Its name.
- nsTtlinteger or nullalways
  The referral's NS TTL, in seconds.
- legintegeralways
  1 for the reverse name's walk; 2 and on for each RFC 2317 CNAME followed.
networkobject or nullalways
The network that announces the address (Team Cymru); null when unknown.
Show 7 fields
- asnintegeralways
  The AS number that announces the address.
- namestringalways
  The network's name, cleaned ("Google", "Amazon.com").
- prefixstringalways
  The announced prefix the address is in, e.g. 8.8.8.0/24.
- countrystringalways
  The network's registration country (ISO 3166-1 alpha-2), as Team Cymru has it.
- asNamestringalways
  The AS name as registered.
- registrystringalways
  The RIR that allocated the block (arin, ripe, apnic, lacnic, afrinic).
- allocatedstring or nullalways
  When the block was allocated (YYYY-MM-DD).
mailobjectalways
The answer against the big mailbox providers' published PTR rules.
- namestring or nullalways
  The name a receiver sees first (a forward-confirmed one when there is one).
- passintegeralways
  Providers whose rules all pass (of 3).
- providersarray of objectsalways
  Gmail, Yahoo Mail and Outlook.com.
  Show 6 fields
  - idstringalways
    The provider.
    one of "gmail", "yahoo", "outlook"
  - ptrstringalways
    A PTR exists: pass, fail, warn, not_required (not part of this provider's rules) or unknown (the lookup couldn't settle it).
    one of "pass", "fail", "warn", "not_required", "unknown"
  - fcrdnsstringalways
    It points back: pass, fail, warn, not_required (not part of this provider's rules) or unknown (the lookup couldn't settle it).
    one of "pass", "fail", "warn", "not_required", "unknown"
  - notGenericstringalways
    It isn't a generic or pool name: pass, fail, warn, not_required (not part of this provider's rules) or unknown (the lookup couldn't settle it).
    one of "pass", "fail", "warn", "not_required", "unknown"
  - passbooleanalways
    Every rule passes.
  - unknownbooleanalways
    No rule fails, but one couldn't be checked.
crawlerobject or nullalways
The crawler check, when a PTR name claims a crawler's domain or the address is in a crawler's published list; null otherwise.
Show 6 fields
- idstringalways
  The crawler's id, e.g. googlebot, bingbot.
- namestringalways
  Its name.
- statusstringalways
  verified, fake (claims the domain, fails both checks), unverified (a check couldn't finish) or cloud (a googleusercontent.com name: any Google Cloud VM).
  one of "verified", "fake", "unverified", "cloud"
- methodstringalways
  How it was decided: ptr (domain + forward lookup), list (published IP list) or both.
  one of "ptr", "list", "both"
- domainstring or nullalways
  The documented domain the name ends in.
- liststring or nullalways
  The published list the address is in.
ptrProviderobject or nullalways
The cloud or ISP to set the PTR at, with its guide, when the address has none, a generic one, or one that doesn't point back.
- idstringalways
  A stable id, e.g. aws.
- namestringalways
  Its name.
- docsstringalways
  Its guide to setting reverse DNS.
copiesarray of objectsalways
Google's and Cloudflare's cached copies (TTLs are the time left).
Show 5 fields
- sourcestringalways
  google or cloudflare.
  one of "google", "cloudflare"
- statusstringalways
  The answer: ok (records came back), nodata (the name exists without them), nxdomain (no such name), servfail, refused, timeout, error or unreadable (an answer our decoder refuses).
  one of "ok", "nodata", "nxdomain", "servfail", "refused", "timeout", "error", "unreadable"
- namesarray of stringsalways
  Its PTR names.
- ttlinteger or nullalways
  The TTL left, in seconds (the miss's, for no PTR).
- tookMsintegeralways
  How long that answer took, in milliseconds.
issuesarray of objectsalways
Problems found in the target's configuration, worst first. Empty when there are none.
- severitystringalways
  error breaks something, warning risks it, info is worth knowing.
  one of "error", "warning", "info"
- codestringalways
  Stable machine-readable code.
- messagestringalways
  The problem and what to do about it, in plain English.

Errors

422 target_not_allowed A private or other special-use address (RFC 1918, loopback, link-local, documentation ranges…), which has no public reverse DNS.

Plus the errors every endpoint can return: 400 for a missing or unreadable parameter, 429 past the limit, 503 when every source failed.

curl "https://dnsrobot.net/api/v2/reverse-dns?ip=8.8.8.8"

const params = new URLSearchParams({ ip: "8.8.8.8" });
const res = await fetch(`https://dnsrobot.net/api/v2/reverse-dns?${params}`);
const data = await res.json();
if (!res.ok) throw new Error(data.error.message);
console.log(data.ptr);

import requests

r = requests.get(
    "https://dnsrobot.net/api/v2/reverse-dns",
    params={"ip": "8.8.8.8"},
    timeout=30,
)
data = r.json()
if not r.ok:
    raise RuntimeError(data["error"]["message"])
print(data["ptr"])

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
)

func main() {
	q := url.Values{"ip": {"8.8.8.8"}}
	res, err := http.Get("https://dnsrobot.net/api/v2/reverse-dns?" + q.Encode())
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	var data map[string]any
	if err := json.NewDecoder(res.Body).Decode(&data); err != nil {
		panic(err)
	}
	if res.StatusCode != http.StatusOK {
		panic(data["error"])
	}
	fmt.Println(data["ptr"])
}

<?php
$query = http_build_query(["ip" => "8.8.8.8"]);
$context = stream_context_create(["http" => ["ignore_errors" => true, "timeout" => 30]]);
$data = json_decode(file_get_contents("https://dnsrobot.net/api/v2/reverse-dns?" . $query, false, $context), true);
if (isset($data["error"])) {
    throw new RuntimeException($data["error"]["message"]);
}
print_r($data["ptr"]);

require "net/http"
require "json"

uri = URI("https://dnsrobot.net/api/v2/reverse-dns")
uri.query = URI.encode_www_form(ip: "8.8.8.8")
data = JSON.parse(Net::HTTP.get(uri))
raise data["error"]["message"] if data["error"]
puts data["ptr"]

// Cargo.toml: reqwest = { version = "0.13", features = ["blocking", "json"] }, serde_json = "1"
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let res = reqwest::blocking::get("https://dnsrobot.net/api/v2/reverse-dns?ip=8.8.8.8")?;
    let ok = res.status().is_success();
    let data: serde_json::Value = res.json()?;
    if !ok {
        return Err(data["error"]["message"].to_string().into());
    }
    println!("{}", data["ptr"]);
    Ok(())
}

using System.Text.Json;

using var http = new HttpClient();
var res = await http.GetAsync("https://dnsrobot.net/api/v2/reverse-dns?ip=8.8.8.8");
var data = JsonDocument.Parse(await res.Content.ReadAsStringAsync()).RootElement;
if (!res.IsSuccessStatusCode)
    throw new Exception(data.GetProperty("error").GetProperty("message").GetString());
Console.WriteLine(data.GetProperty("ptr"));

8.8.8.8: dns.google

GET /api/v2/reverse-dns?ip=8.8.8.8

200 OKRecorded 2026-10-25

{
  "query": {
    "ip": "8.8.8.8"
  },
  "ip": "8.8.8.8",
  "reverseName": "8.8.8.8.in-addr.arpa",
  "specialUse": null,
  "verdict": "confirmed",
  "role": "resolver",
  "ptr": [
    {
      "name": "dns.google",
      "ttl": 86400,
      "forwardConfirmed": true,
      "ipv4": [
        "8.8.8.8",
        "8.8.4.4"
      ],
      "ipv6": [
        "2001:4860:4860::8844",
        "2001:4860:4860::8888"
      ],
      "kind": "named"
    }
  ],
  "forwardConfirmed": true,
  "answer": {
    "source": "authoritative",
    "server": "ns2.google.com",
    "ip": "216.239.34.10",
    "viaCloudflare": false,
    "status": "ok",
    "rcode": "NOERROR",
    "authoritative": true,
    "negativeTtl": null,
    "cnameChain": []
  },
  "zone": {
    "name": "8.8.8.in-addr.arpa",
    "operator": {
      "kind": "holder",
      "id": "google",
      "name": "Google"
    }
  },
  "delegation": [
    {
      "zone": ".",
      "server": "b.root-servers.net",
      "ip": "170.247.170.2",
      "outcome": "referral",
      "operator": {
        "kind": "root",
        "id": "root",
        "name": "Root"
      },
      "nsTtl": 172800,
      "leg": 1
    },
    {
      "zone": "in-addr.arpa",
      "server": "f.in-addr-servers.arpa",
      "ip": "193.0.9.1",
      "outcome": "referral",
      "operator": {
        "kind": "iana",
        "id": "iana",
        "name": "IANA"
      },
      "nsTtl": 86400,
      "leg": 1
    },
    {
      "zone": "8.in-addr.arpa",
      "server": "arin.authdns.ripe.net",
      "ip": "193.0.9.10",
      "outcome": "referral",
      "operator": {
        "kind": "rir",
        "id": "arin",
        "name": "ARIN"
      },
      "nsTtl": 86400,
      "leg": 1
    },
    // … 1 more item
  ],
  "network": {
    "asn": 15169,
    "name": "Google",
    "asName": "GOOGLE - Google LLC, US",
    "prefix": "8.8.8.0/24",
    "country": "US",
    "registry": "arin",
    "allocated": "2023-12-28"
  },
  "mail": {
    "name": "dns.google",
    "pass": 3,
    "providers": [
      {
        "id": "gmail",
        "ptr": "pass",
        "fcrdns": "pass",
        "notGeneric": "not_required",
        "pass": true,
        "unknown": false
      },
      {
        "id": "yahoo",
        "ptr": "pass",
        "fcrdns": "pass",
        "notGeneric": "pass",
        "pass": true,
        "unknown": false
      },
      {
        "id": "outlook",
        "ptr": "pass",
        "fcrdns": "not_required",
        "notGeneric": "pass",
        "pass": true,
        "unknown": false
      }
    ]
  },
  "crawler": null,
  "ptrProvider": null,
  "copies": [
    {
      "source": "google",
      "status": "ok",
      "names": [
        "dns.google"
      ],
      "ttl": 1040,
      "tookMs": 33
    },
    {
      "source": "cloudflare",
      "status": "ok",
      "names": [
        "dns.google"
      ],
      "ttl": 79471,
      "tookMs": 1
    }
  ],
  "issues": [],
  "tookMs": 2314
}

Shortened for the page: long lists show their first items.

A Googlebot address, verified

GET /api/v2/reverse-dns?ip=66.249.66.1

200 OKRecorded 2026-10-25

{
  "query": {
    "ip": "66.249.66.1"
  },
  "ip": "66.249.66.1",
  "reverseName": "1.66.249.66.in-addr.arpa",
  "specialUse": null,
  "verdict": "crawler",
  "role": "crawler",
  "ptr": [
    {
      "name": "crawl-66-249-66-1.googlebot.com",
      "ttl": 86400,
      "forwardConfirmed": true,
      "ipv4": [
        "66.249.66.1"
      ],
      "ipv6": [],
      "kind": "crawler"
    }
  ],
  "forwardConfirmed": true,
  "answer": {
    "source": "authoritative",
    "server": "ns2.google.com",
    "ip": "216.239.34.10",
    "viaCloudflare": false,
    "status": "ok",
    "rcode": "NOERROR",
    "authoritative": true,
    "negativeTtl": null,
    "cnameChain": []
  },
  "zone": {
    "name": "66.249.66.in-addr.arpa",
    "operator": {
      "kind": "holder",
      "id": "google",
      "name": "Google"
    }
  },
  "delegation": [
    {
      "zone": ".",
      "server": "c.root-servers.net",
      "ip": "192.33.4.12",
      "outcome": "referral",
      "operator": {
        "kind": "root",
        "id": "root",
        "name": "Root"
      },
      "nsTtl": 172800,
      "leg": 1
    },
    {
      "zone": "in-addr.arpa",
      "server": "c.in-addr-servers.arpa",
      "ip": "196.216.169.10",
      "outcome": "referral",
      "operator": {
        "kind": "iana",
        "id": "iana",
        "name": "IANA"
      },
      "nsTtl": 86400,
      "leg": 1
    },
    {
      "zone": "66.in-addr.arpa",
      "server": "arin.authdns.ripe.net",
      "ip": "193.0.9.10",
      "outcome": "referral",
      "operator": {
        "kind": "rir",
        "id": "arin",
        "name": "ARIN"
      },
      "nsTtl": 86400,
      "leg": 1
    },
    // … 1 more item
  ],
  "network": {
    "asn": 15169,
    "name": "Google",
    "asName": "GOOGLE - Google LLC, US",
    "prefix": "66.249.64.0/20",
    "country": "US",
    "registry": "arin",
    "allocated": "2004-03-05"
  },
  "mail": {
    "name": "crawl-66-249-66-1.googlebot.com",
    "pass": 3,
    "providers": [
      {
        "id": "gmail",
        "ptr": "pass",
        "fcrdns": "pass",
        "notGeneric": "not_required",
        "pass": true,
        "unknown": false
      },
      {
        "id": "yahoo",
        "ptr": "pass",
        "fcrdns": "pass",
        "notGeneric": "pass",
        "pass": true,
        "unknown": false
      },
      {
        "id": "outlook",
        "ptr": "pass",
        "fcrdns": "not_required",
        "notGeneric": "pass",
        "pass": true,
        "unknown": false
      }
    ]
  },
  "crawler": {
    "id": "googlebot",
    "name": "Googlebot",
    "status": "verified",
    "method": "both",
    "domain": "googlebot.com",
    "list": "common-crawlers"
  },
  "ptrProvider": null,
  "copies": [
    {
      "source": "google",
      "status": "ok",
      "names": [
        "crawl-66-249-66-1.googlebot.com"
      ],
      "ttl": 4993,
      "tookMs": 43
    },
    {
      "source": "cloudflare",
      "status": "ok",
      "names": [
        "crawl-66-249-66-1.googlebot.com"
      ],
      "ttl": 84702,
      "tookMs": 1
    }
  ],
  "issues": [],
  "tookMs": 1580
}

Shortened for the page: long lists show their first items.

Cloudflare's resolver over IPv6

GET /api/v2/reverse-dns?ip=2606%3A4700%3A4700%3A%3A1111

200 OKRecorded 2026-10-25

{
  "query": {
    "ip": "2606:4700:4700::1111"
  },
  "ip": "2606:4700:4700::1111",
  "reverseName": "1.1.1.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.7.4.0.0.7.4.6.0.6.2.ip6.arpa",
  "specialUse": null,
  "verdict": "confirmed",
  "role": "resolver",
  "ptr": [
    {
      "name": "one.one.one.one",
      "ttl": 1800,
      "forwardConfirmed": true,
      "ipv4": [
        "1.0.0.1",
        "1.1.1.1"
      ],
      "ipv6": [
        "2606:4700:4700::1111",
        "2606:4700:4700::1001"
      ],
      "kind": "named"
    }
  ],
  "forwardConfirmed": true,
  "answer": {
    "source": "authoritative",
    "server": "one.one.one.one",
    "ip": "1.1.1.1",
    "viaCloudflare": true,
    "status": "ok",
    "rcode": "NOERROR",
    "authoritative": false,
    "negativeTtl": null,
    "cnameChain": []
  },
  "zone": {
    "name": "0.0.7.4.6.0.6.2.ip6.arpa",
    "operator": {
      "kind": "holder",
      "id": "cloudflare",
      "name": "Cloudflare"
    }
  },
  "delegation": [
    {
      "zone": ".",
      "server": "d.root-servers.net",
      "ip": "199.7.91.13",
      "outcome": "referral",
      "operator": {
        "kind": "root",
        "id": "root",
        "name": "Root"
      },
      "nsTtl": 172800,
      "leg": 1
    },
    {
      "zone": "ip6.arpa",
      "server": "f.ip6-servers.arpa",
      "ip": "193.0.9.2",
      "outcome": "referral",
      "operator": {
        "kind": "iana",
        "id": "iana",
        "name": "IANA"
      },
      "nsTtl": 86400,
      "leg": 1
    },
    {
      "zone": "0.6.2.ip6.arpa",
      "server": "u.arin.net",
      "ip": "204.61.216.50",
      "outcome": "referral",
      "operator": {
        "kind": "rir",
        "id": "arin",
        "name": "ARIN"
      },
      "nsTtl": 1800,
      "leg": 1
    },
    // … 1 more item
  ],
  "network": {
    "asn": 13335,
    "name": "Cloudflare",
    "asName": "CLOUDFLARENET - Cloudflare, Inc., US",
    "prefix": "2606:4700:4700::/48",
    "country": "US",
    "registry": "arin",
    "allocated": "2011-11-01"
  },
  "mail": {
    "name": "one.one.one.one",
    "pass": 3,
    "providers": [
      {
        "id": "gmail",
        "ptr": "pass",
        "fcrdns": "pass",
        "notGeneric": "not_required",
        "pass": true,
        "unknown": false
      },
      {
        "id": "yahoo",
        "ptr": "pass",
        "fcrdns": "pass",
        "notGeneric": "pass",
        "pass": true,
        "unknown": false
      },
      {
        "id": "outlook",
        "ptr": "pass",
        "fcrdns": "not_required",
        "notGeneric": "pass",
        "pass": true,
        "unknown": false
      }
    ]
  },
  "crawler": null,
  "ptrProvider": null,
  "copies": [
    {
      "source": "google",
      "status": "ok",
      "names": [
        "one.one.one.one"
      ],
      "ttl": 727,
      "tookMs": 38
    },
    {
      "source": "cloudflare",
      "status": "ok",
      "names": [
        "one.one.one.one"
      ],
      "ttl": 1800,
      "tookMs": 258
    }
  ],
  "issues": [],
  "tookMs": 471
}

Shortened for the page: long lists show their first items.

Reverse DNS API

How it works

Query parameters

Response fields

Errors

Code samples