There is no significant difference. Both sites are operated by the same company, 1xCorp N.V., or something like that. The only differences are in the frontend design and the fact that 1xbit does not have a license, so it operates illegally. Re: What is the Different Between 1XBet and 1XBit?
The three Russian founders of 1xBet, Roman Semiokhin, Sergey Karshkov and Dmitry Kazorin, are all from the city of Brjansk, some 370 kilometres west of Moscow, although all three currently live in Cyprus.