/users/{username} returns a user, but not github.com/{username}

I use the GitHub Api to query specific users. If the user does not exist, e.g. octocat5412358, I correctly receive a “404 - Not found”.

But with the user “Zarcc” (https://api.github.com/users/zarcc), the API returns a user. When I try to use the url returned from the request (https://github.com/zarcc) I land on the Github 404 page. Is this user inactive/deleted and how can I see this in the API?

I think this user no longer exists. I say this because the GitHub api v4 says that it cannot find the user. I would use the GraphQL (GitHub api v4) api if you want the most accurate result, though it is not the best for everything. This is a great tool for figuring out how it works. https://developer.github.com/v4/explorer/