Is the name actually free?
Type a business name and this checks a dozen domain endings at the same time, against the registries themselves rather than a reseller's list. No account, nothing stored, and no upsell.
Twelve endings, checked at the same time. Nothing is stored.
What this can and cannot tell you. It asks each registry whether a registration record exists. No record is a good sign and not a promise: a name can be reserved, held back by the registry, premium priced, or taken between this check and your checkout. A registered domain also says nothing about whether the trademark is free. Anything that does not answer in time is marked so, rather than counted as available.