SLD (Second-Level Domain)
An SLD (second-level domain) is the label directly to the left of the TLD — in example.com, the SLD is example. When investors talk about a domain's quality, they are almost always talking about the SLD: its length, its words, its memorability. The TLD sets the market; the SLD is the asset.
How SLDs fit in the hierarchy
A domain name reads right to left in the DNS hierarchy: TLD, then SLD, then optional subdomains (third level and beyond, like www or app). One nuance: some ccTLDs sell registrations at the third level under an official second level — co.uk is the classic case, where your registrable name sits under the .co.uk suffix.
What makes an SLD valuable
- •Length: shorter is better; one-word and 2-3 character SLDs command the strongest premiums.
- •Meaning: real dictionary words, product categories, and pronounceable brandables lead the market.
- •Cleanliness: no hyphens, no digits (unless purely numeric), no trademark exposure.
- •The same SLD can be worth wildly different amounts across TLDs — the .com usually anchors the top of the range.
Frequently Asked Questions
Is www part of the SLD?
No. www is a subdomain (a third-level label) under the SLD. Registering example.com gives you control of every subdomain beneath it at no extra cost.
What is the shortest SLD you can register?
Depends on the registry. Many TLDs reserve or premium-price one- and two-character SLDs; where available, they are among the most valuable strings in the extension.