What Is An SLD?

Date First Published: 9th April 2022

Topic: Computer Networking

Subtopic: Network Identifiers

Article Type: Computer Terms & Definitions

Difficulty Level: 5/10

Learn more about what an SLD is in this article.

Short for a second-level domain, an SLD, also known as a 2LD is the custom name that appears before the TLD, usually com, net, or org. For example, in ‘example.com’, ‘example’ is the SLD and ‘com’ is the TLD. SLDs are directly below TLDs and they are located to the left of the TLD before the dot. The SLD usually contains the name of the company, project, or website and can contain alphanumeric characters.

Note that the SLD does not have an effect on the price of a domain name. The price of a domain name is based on the TLD, meaning the domain name extension, and the amount of money it costs for a domain registrar to register it. For example, if the two domain names ‘example.com’ and ‘website.com’ were available, there would be no difference in price between these two SLDs. In other words, the custom name that appears before the dot will never have an effect on the price. An SLD along with a TLD can be registered if the domain name is available and not already registered.

Limitations

SLDs can contain letters, numbers, and hyphens (-). Any other characters (#,*&^%$£”!@/|.) are disallowed in an SLD. SLDs cannot start with a hyphen, such as ‘-example.com’. However, they can start with a number, such as ‘1example.com’.

Note:

SLDs must contain at least 2 characters and the maximum length is 63 characters. Note that the maximum length is the part before the TLD.

ccSLDs

Country-code second-level domains are located to the right of the SLD. For example, in ‘amazon.co.uk’, the ccSLD is ‘.co’ and the ccTLD is ‘.uk’.