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API Reference
Registrar

Check domain availability

POST/accounts/{account_id}/registrar/domain-check

Performs real-time, authoritative availability checks directly against domain registries. Use this endpoint to verify a domain is available before attempting registration via POST /registrations.

Important: Unlike the Search endpoint, these results are authoritative and reflect current registry status. Always check availability immediately before registration as domain status can change rapidly.

Note: This endpoint uses POST to accept a list of domains in the request body. It is a read-only operation — it does not create, modify, or reserve any domains.

Extension support

Only domains on extensions supported for programmatic registration by this API can be registered. If you check a domain on an unsupported extension, the response will include registrable: false with a reason field explaining why:

  • extension_not_supported_via_api — Cloudflare Registrar supports this extension in the dashboard, but it is not yet available for programmatic registration via this API. Register via https://dash.cloudflare.com/{account_id}/domains/registrations instead.
  • extension_not_supported — This extension is not supported by Cloudflare Registrar.
  • extension_disallows_registration — The extension’s registry has temporarily or permanently frozen new registrations. No registrar can register domains on this extension at this time.
  • domain_premium — The domain is premium priced. Premium registration is not currently supported by this API.
  • domain_unavailable — The domain is already registered, reserved, or otherwise not available for registration on a supported extension.

The reason field is only present when registrable is false.

Behavior

  • Maximum 20 domains per request
  • Pricing is only returned for domains where registrable: true
  • Results are not cached; each request queries the registry

Workflow

  1. Call this endpoint with domains the user wants to register.
  2. For each domain where registrable: true, present pricing to the user.
  3. If tier: premium, note that premium registration is not currently supported by this API and do not proceed to POST /registrations.
  4. Proceed to POST /registrations only for supported non-premium domains.
Security
API Token

The preferred authorization scheme for interacting with the Cloudflare API. Create a token.

Example:Authorization: Bearer Sn3lZJTBX6kkg7OdcBUAxOO963GEIyGQqnFTOFYY
API Email + API Key

The previous authorization scheme for interacting with the Cloudflare API, used in conjunction with a Global API key.

Example:X-Auth-Email: user@example.com

The previous authorization scheme for interacting with the Cloudflare API. When possible, use API tokens instead of Global API keys.

Example:X-Auth-Key: 144c9defac04969c7bfad8efaa8ea194
Path ParametersExpand Collapse
account_id: optional string

Identifier

maxLength32
Body ParametersJSONExpand Collapse
domains: array of string

List of fully qualified domain names (FQDNs) to check for availability. Each domain must include the extension.

  • Minimum: 1 domain
  • Maximum: 20 domains per request
  • Domains on unsupported extensions are returned with registrable: false and a reason field
  • Malformed domain names (e.g., missing extension) may be omitted from the response
ReturnsExpand Collapse
errors: array of ResponseInfo { code, message, documentation_url, source }
code: number
minimum1000
message: string
documentation_url: optional string
source: optional { pointer }
pointer: optional string
messages: array of ResponseInfo { code, message, documentation_url, source }
code: number
minimum1000
message: string
documentation_url: optional string
source: optional { pointer }
pointer: optional string
result: { domains }

Contains the availability check results.

domains: array of { name, registrable, pricing, 2 more }

Array of domain availability results. Domains on unsupported extensions are included with registrable: false and a reason field. Malformed domain names may be omitted.

name: string

The fully qualified domain name (FQDN) in punycode format for internationalized domain names (IDNs).

registrable: boolean

Indicates whether this domain can be registered programmatically through this API based on a real-time registry check.

  • true: Domain is available for registration. The pricing object will be included.
  • false: Domain is not available. See the reason field for why. tier may still be present on some non-registrable results, such as premium domains.
pricing: optional { currency, registration_cost, renewal_cost }

Annual pricing information for a registrable domain. This object is only present when registrable is true. All prices are per year and returned as strings to preserve decimal precision.

registration_cost and renewal_cost are frequently the same value, but may differ — especially for premium domains where registries set different rates for initial registration vs. renewal. For a multi-year registration (e.g., 4 years), the first year is charged at registration_cost and each subsequent year at renewal_cost. Registry pricing may change over time; the values returned here reflect the current registry rate. Premium pricing may be surfaced by Search and Check, but premium registration is not currently supported by this API.

currency: string

ISO-4217 currency code for the prices (e.g., “USD”, “EUR”, “GBP”).

registration_cost: string

The first-year cost to register this domain. For premium domains (tier: premium), this price is set by the registry and may be significantly higher than standard pricing. For multi-year registrations, this cost applies to the first year only; subsequent years are charged at renewal_cost.

renewal_cost: string

Per-year renewal cost for this domain. Applied to each year beyond the first year of a multi-year registration, and to each annual auto-renewal thereafter. May differ from registration_cost, especially for premium domains where initial registration often costs more than renewals.

reason: optional "extension_not_supported_via_api" or "extension_not_supported" or "extension_disallows_registration" or 2 more

Present only when registrable is false. Explains why the domain cannot be registered via this API.

  • extension_not_supported_via_api: Cloudflare Registrar supports this extension in the dashboard but it is not yet available for programmatic registration via this API. The user can register via https://dash.cloudflare.com/{account_id}/domains/registrations.
  • extension_not_supported: This extension is not supported by Cloudflare Registrar at all.
  • extension_disallows_registration: The extension’s registry has temporarily or permanently frozen new registrations. No registrar can register domains on this extension at this time.
  • domain_premium: The domain is premium priced. Premium registration is not currently supported by this API.
  • domain_unavailable: The domain is already registered, reserved, or otherwise not available on a supported extension.
One of the following:
"extension_not_supported_via_api"
"extension_not_supported"
"extension_disallows_registration"
"domain_premium"
"domain_unavailable"
tier: optional "standard" or "premium"

The pricing tier for this domain. Always present when registrable is true; defaults to standard for most domains. May be absent when registrable is false.

  • standard: Standard registry pricing
  • premium: Premium domain with higher pricing set by the registry
One of the following:
"standard"
"premium"
success: true

Whether the API call was successful

Check domain availability

curl https://api.cloudflare.com/client/v4/accounts/$ACCOUNT_ID/registrar/domain-check \
    -H 'Content-Type: application/json' \
    -H "Authorization: Bearer $CLOUDFLARE_API_TOKEN" \
    -d '{
          "domains": [
            "myawesomebrand.com",
            "myawesomebrand.net",
            "myawesomebrand.org",
            "myawesomebrand.app",
            "myawesomebrand.dev"
          ]
        }'
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "xq7mz9brand.com",
        "pricing": {
          "currency": "USD",
          "registration_cost": "8.57",
          "renewal_cost": "8.57"
        },
        "registrable": true,
        "tier": "standard"
      },
      {
        "name": "xq7mz9brand.net",
        "pricing": {
          "currency": "USD",
          "registration_cost": "9.95",
          "renewal_cost": "9.95"
        },
        "registrable": true,
        "tier": "standard"
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "example.com",
        "reason": "domain_unavailable",
        "registrable": false
      },
      {
        "name": "example.net",
        "reason": "domain_unavailable",
        "registrable": false
      },
      {
        "name": "example.org",
        "reason": "domain_unavailable",
        "registrable": false
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "cloudflare.com",
        "reason": "domain_unavailable",
        "registrable": false
      },
      {
        "name": "my-unique-startup-name-2024.com",
        "pricing": {
          "currency": "USD",
          "registration_cost": "8.57",
          "renewal_cost": "8.57"
        },
        "registrable": true,
        "tier": "standard"
      },
      {
        "name": "my-unique-startup-name-2024.dev",
        "pricing": {
          "currency": "USD",
          "registration_cost": "10.11",
          "renewal_cost": "10.11"
        },
        "registrable": true,
        "tier": "standard"
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "coffee.xyz",
        "reason": "domain_premium",
        "registrable": false,
        "tier": "premium"
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "example.py",
        "reason": "extension_disallows_registration",
        "registrable": false
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "example.horse",
        "reason": "extension_not_supported",
        "registrable": false
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "mybrand.uk",
        "reason": "extension_not_supported_via_api",
        "registrable": false
      },
      {
        "name": "mybrand.com",
        "pricing": {
          "currency": "USD",
          "registration_cost": "8.57",
          "renewal_cost": "8.57"
        },
        "registrable": true,
        "tier": "standard"
      }
    ]
  },
  "success": true
}
{
  "errors": [
    {
      "code": 1006,
      "message": "domains array must contain at least one domain"
    }
  ],
  "messages": [],
  "result": null,
  "success": false
}
{
  "errors": [
    {
      "code": 1008,
      "message": "None of the provided domains are valid or have supported extensions"
    }
  ],
  "messages": [],
  "result": null,
  "success": false
}
{
  "errors": [
    {
      "code": 1007,
      "message": "domains array exceeds maximum of 20 domains"
    }
  ],
  "messages": [],
  "result": null,
  "success": false
}
Returns Examples
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "xq7mz9brand.com",
        "pricing": {
          "currency": "USD",
          "registration_cost": "8.57",
          "renewal_cost": "8.57"
        },
        "registrable": true,
        "tier": "standard"
      },
      {
        "name": "xq7mz9brand.net",
        "pricing": {
          "currency": "USD",
          "registration_cost": "9.95",
          "renewal_cost": "9.95"
        },
        "registrable": true,
        "tier": "standard"
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "example.com",
        "reason": "domain_unavailable",
        "registrable": false
      },
      {
        "name": "example.net",
        "reason": "domain_unavailable",
        "registrable": false
      },
      {
        "name": "example.org",
        "reason": "domain_unavailable",
        "registrable": false
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "cloudflare.com",
        "reason": "domain_unavailable",
        "registrable": false
      },
      {
        "name": "my-unique-startup-name-2024.com",
        "pricing": {
          "currency": "USD",
          "registration_cost": "8.57",
          "renewal_cost": "8.57"
        },
        "registrable": true,
        "tier": "standard"
      },
      {
        "name": "my-unique-startup-name-2024.dev",
        "pricing": {
          "currency": "USD",
          "registration_cost": "10.11",
          "renewal_cost": "10.11"
        },
        "registrable": true,
        "tier": "standard"
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "coffee.xyz",
        "reason": "domain_premium",
        "registrable": false,
        "tier": "premium"
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "example.py",
        "reason": "extension_disallows_registration",
        "registrable": false
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "example.horse",
        "reason": "extension_not_supported",
        "registrable": false
      }
    ]
  },
  "success": true
}
{
  "errors": [],
  "messages": [],
  "result": {
    "domains": [
      {
        "name": "mybrand.uk",
        "reason": "extension_not_supported_via_api",
        "registrable": false
      },
      {
        "name": "mybrand.com",
        "pricing": {
          "currency": "USD",
          "registration_cost": "8.57",
          "renewal_cost": "8.57"
        },
        "registrable": true,
        "tier": "standard"
      }
    ]
  },
  "success": true
}
{
  "errors": [
    {
      "code": 1006,
      "message": "domains array must contain at least one domain"
    }
  ],
  "messages": [],
  "result": null,
  "success": false
}
{
  "errors": [
    {
      "code": 1008,
      "message": "None of the provided domains are valid or have supported extensions"
    }
  ],
  "messages": [],
  "result": null,
  "success": false
}
{
  "errors": [
    {
      "code": 1007,
      "message": "domains array exceeds maximum of 20 domains"
    }
  ],
  "messages": [],
  "result": null,
  "success": false
}