Verify any domain extension and identify its managing registry.
TLD Lookup retrieves information about any top-level domain including its type (generic, country-code, sponsored) and the sponsoring organization responsible for managing it.
Try it — live request, no key required
No key required to try it. Get a key to use it in your app.
{
"status": "ok",
"error": null,
"data": {
"tld": "com",
"found": true,
"type": "generic",
"organization": "VeriSign Global Registry Services"
}
}
About the TLD Lookup API
TLD Lookup uses an authoritative database of all IANA-registered top-level domains. This includes legacy TLDs like .com and .org, country-code TLDs like .uk and .de, and newer generic TLDs like .app and .dev.
What people use it for
- Domain Validation
- Verify that a TLD is valid and registered with IANA before processing user-submitted domains
- Phishing Detection
- Identify domains using unusual or newly-created TLDs that may indicate phishing attempts
- Domain Analysis
- Understand the type and ownership of domain extensions for research and compliance purposes
- Registrar Tools
- Look up TLD information to determine registration requirements and managing organizations
Ways to call it
One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.
- JSON
- Default REST response
- XML
- Markup format
- YAML
- Human-readable
- CSV
- Tabular export
- GraphQL
- Query language
- MCP
- For AI agents
Other ways to use TLD Lookup
Same data, same APIVerve account, same credit balance — one key works on all of them.
Which types of top-level domains can I look up?
Where does the domain data come from and how fresh is it?
Is it cheap enough to verify the TLD for every domain submission?
What happens if someone submits an unregistered extension or includes a leading dot?
Can I use TLD data inside my commercial security or validation tool?
Request parameters — GET /v1/tldlookup
Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.
Required
| Parameter | Type | Example | Description |
|---|---|---|---|
tldRequired | string | com | The top-level domain to look up (with or without leading dot) |
curl "https://api.apiverve.com/v1/tldlookup?tld=com" \
-H "x-api-key: YOUR_API_KEY"Authentication
Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.
| Header | When | Value |
|---|---|---|
x-api-keyRequired | Every request | Your API key. Header names are case-insensitive, so X-API-Key is the same header. |
AuthorizationAlternate | Instead of the above | Bearer <key> — for clients that only expose bearer auth. Resolves to the same account and the same billing. |
A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.
Response — GET /v1/tldlookup
Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.
{
"status": "ok",
"error": null,
"data": {
"tld": "com",
"found": true,
"type": "generic",
"organization": "VeriSign Global Registry Services"
}
}
Response fields
Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.
| Field | Type | Example | Description |
|---|---|---|---|
tld | string | "com" | The top-level domain requested in normalized form |
found | boolean | true | Whether the TLD is registered with IANA |
type | string | "generic" | TLD type: generic, country-code, sponsored, infrastructure |
organization | string | "VeriSign Global Registry Services" | Organization responsible for managing the TLD |
Response headers
Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.
| Header | What it carries |
|---|---|
x-api-remaining-credits | Credits left in the current cycle |
x-api-credits-used | Credits spent in the current cycle |
x-api-max-credits | The allowance for the cycle |
x-api-version | Version of the endpoint that answered |
Errors
Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.
| Status | Meaning | What to do |
|---|---|---|
400 | Input was rejected | Read error; it names the parameter that has to change. |
401 | Key missing or invalid | Check the header name and the key value. |
403 | Key valid, but not permitted here | A key restriction or an IP allow-list — never a bad key. |
429 | Rate limited, or out of credits | Read error to tell them apart, then back off or top up. |
What a call costs — 2 credits per call
Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.
| Plan | Per month | Credits | TLD Lookup calls | Per 1,000 calls |
|---|---|---|---|---|
| Free | Free | 200 | 100 | Free |
| Starter | $29.99 | 200,000 | 100,000 | $0.30 |
| Pro | $99.99 | 1,000,000 | 500,000 | $0.20 |
| Mega | $299.99 | 4,000,000 | 2,000,000 | $0.15 |
Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.
Call it from cURL — GET /v1/tldlookup
No SDK to install — this is a plain HTTPS call to /v1/tldlookup with your key in the x-api-key header. Swap in a real key and it runs as-is.
curl "https://api.apiverve.com/v1/tldlookup" \
-H "x-api-key: YOUR_API_KEY"Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Node.js — GET /v1/tldlookup
Install the Node.js SDK, then call the TLD Lookup API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.
npm install @apiverve/tldlookupconst res = await fetch("https://api.apiverve.com/v1/tldlookup", {
headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Python — GET /v1/tldlookup
No SDK to install — this is a plain HTTPS call to /v1/tldlookup with your key in the x-api-key header. Swap in a real key and it runs as-is.
import requests
res = requests.get(
"https://api.apiverve.com/v1/tldlookup",
headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from C# / .NET — GET /v1/tldlookup
Install the C# / .NET SDK, then call the TLD Lookup API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.
dotnet add package APIVerve.API.TLDLookupusing var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");
var json = await client.GetStringAsync("https://api.apiverve.com/v1/tldlookup");
Console.WriteLine(json);Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Go — GET /v1/tldlookup
No SDK to install — this is a plain HTTPS call to /v1/tldlookup with your key in the x-api-key header. Swap in a real key and it runs as-is.
req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/tldlookup", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from PHP — GET /v1/tldlookup
No SDK to install — this is a plain HTTPS call to /v1/tldlookup with your key in the x-api-key header. Swap in a real key and it runs as-is.
$ch = curl_init("https://api.apiverve.com/v1/tldlookup");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);
$response = curl_exec($ch);
echo $response;Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Ruby — GET /v1/tldlookup
No SDK to install — this is a plain HTTPS call to /v1/tldlookup with your key in the x-api-key header. Swap in a real key and it runs as-is.
require "net/http"
uri = URI("https://api.apiverve.com/v1/tldlookup")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"
res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.bodyResources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Zero-code embed — one snippet, no backend
Drop an interactive TLD Lookup form onto any page. The widget calls the API for you, so no key ever appears in your markup and there is nothing to deploy.
Changelog — TLD Lookup API
Every change to this endpoint, newest first. Breaking changes ship as a new version and the previous one keeps serving — response fields are added, never removed or retyped in place, so an integration written against v1 keeps working.
Entries are picked up from dated catalog snapshots, so the first one appears after the next snapshot that moves something. A period where nothing changed produces no entry — silence is a valid changelog for the TLD Lookup API.
Networking
- Bluetooth Company Lookup
- Bot Detector
- Content Filter
- Domain and IP Pinger
- IP Blacklist Lookup
- IP Lookup
- MAC Address Lookup
- Nameservers
- Phishing Domain Checker
- TLD Lookup
- TLS Checker
- Tor Node Detector
- USB Vendor Lookup
- VPN Proxy Detector
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