Domain

GET/v0/domain

Validates a domain name and performs a DNS lookup. Returns the top-level domain (TLD), second-level domain (SLD), whether it is an Internationalized Domain Name (IDN), and whether DNS A/AAAA records exist.

Guides: Node.js · Python

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Query Parameters

Parameter	Type	Required	Description
value	string	Yes	Domain name to validate (e.g. `example.com`, `sub.example.co.uk`)

Example Requests

curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.isvalid.dev/v0/domain?value=example.com"

Response Fields

Field	Type	Description
valid	boolean	Whether the value is a syntactically valid domain name
domain	string	Normalised domain name (lowercase, no trailing dot)
tld	string	Top-level domain (e.g. `com`, `org`, `dev`)
sld	string \| null	Second-level domain (e.g. `example` in `example.com`)
isIDN	boolean	Whether any label is an Internationalized Domain Name (Punycode `xn--` prefix)
dnsValid	boolean	Whether DNS A or AAAA records exist for the domain
hasA	boolean	Whether a DNS A record (IPv4) exists
hasAAAA	boolean	Whether a DNS AAAA record (IPv6) exists

Example Response

{
  "valid": true,
  "domain": "example.com",
  "tld": "com",
  "sld": "example",
  "isIDN": false,
  "dnsValid": true,
  "hasA": true,
  "hasAAAA": true
}

Example Response — invalid

{
  "valid": false
}