Can ICANN Lookup Be Used to Look Up Internet Number Resources?

Yes. ICANN Lookup is not limited to domain names: the tool also lets you look up registration data for Internet number resources. You can use it when you need to check who is recorded as holding a block of IP addresses or an autonomous system number (ASN), rather than who registered a domain. The results are registration records, not a live trace of where traffic goes or who is using an address right now.

What the tool covers

ICANN describes its lookup tool as providing current registration data for both domain names and Internet number resources. In practice that means two different record types sit behind the same interface:

• Domain name records — registration details associated with a domain, such as registrar and registration status information.
• Internet number resource records — registration details associated with allocated or assigned number blocks, such as IP address ranges and ASNs.

The distinction matters because the two record types answer different questions. A domain lookup tells you about a name; a number resource lookup tells you about an address block or routing identifier.

What a number resource lookup can return

When you query a number resource, expect registry-style registration data rather than website or hosting details. Depending on the resource, records may include:

Exact fields vary by resource and by the registry that maintains the record, so treat any single result as a snapshot of one registry's data rather than a complete picture.

How this differs from a domain name lookup

A domain lookup is organized around a name and its registration lifecycle — who registered it, through which registrar, and in what status. A number resource lookup is organized around a block of addresses or an ASN and its allocation history within the regional and global registry system.

Practical consequences:

• Different responsible parties. Domain records are typically maintained through registrars and registries; number resource records sit with the organizations that allocate address space.
• Different identifiers. You search with an IP range or ASN instead of a domain string.
• Different expectations about contacts. Number resource records often point to organizational or registry references rather than the kind of registrant contact data associated with domains.

Limits to keep in mind

The tool displays registration data — it does not show real-time usage, geolocation, or the identity of every device behind an address. A few boundaries are worth setting expectations around:

• Records reflect what is registered, not what is active. An address block can be recorded to one holder while being used by others downstream.
• Coverage depends on the maintaining registry. If a record is not present or is incomplete, the lookup cannot invent it.
• Privacy and redaction apply. Registration data may be limited or redacted, particularly for domain records, and number resource records can likewise be partial.
• No pricing or account signals are published on the tool itself. Nothing in the available description indicates a paid tier or login requirement, so do not assume either way; check the site directly if access terms matter to you.

When to use it

Use ICANN Lookup for number resources when you need to confirm the recorded holder or status of an IP block or ASN — for example, when verifying an allocation before contacting the responsible organization, or when cross-checking a record against another registry's data. Use a domain lookup instead when your question is about a domain name's registration. If your question is about live network behavior rather than registration, this tool is the wrong instrument.