TLDExtractor

C# Library

TLDExtractor is similar to tldextract library (in Python). By using TLDExtractor, you can accurately extract subdomain, domain, and domain suffix (effective TLD) of a given domain name.

It is a common mistake to split a domain name with '.' character and consider the last part as a domain suffix. For example, consider 'www.yahoo.co.uk', in this domain, 'co.uk' is the suffix not 'uk'.

TLDExtractor utilize the Public Suffix List to correctly identify the suffix for a given domain name. To extract subdomain, domain, and domain suffix, you can use TLDExtractor.Extract methods:

var result = TLDExtractor.Extract("www.yahoo.co.uk"); // result.ToString() -> // {ExtractResult(subdomain='www', domain='yahoo', suffix='co.uk', suffix type='ICANN')} // nom.ae is a private suffix submitted by Dave McCormack <dave.mccormack@nymnom.com> var result = TLDExtractor.Extract("www.test.nom.ae"); // result.ToString() -> // {ExtractResult(subdomain='www', domain='test', suffix='nom.ae', suffix type='Private')} // you can pass a Uri Uri guestUrl = new Uri("http://www.example.com/mine.html"); var result = TLDExtractor.Extract(guestUrl); // result.ToString() -> // {ExtractResult(subdomain='www', domain='example', suffix='com', suffix type='ICANN')}

If the domain name is not valid, TLDExtractor.Extract raises TLDExtractorException with an appropriate message explaining the problem. According to RFC 1035, domain names must be equal or less than 255 characters, and each label such as or must be equal or less than 63 characters. Moreover, domain labels cannot be empty. For example, test..com is not valid.