"Most “free” websites subsist by selling ads or selling user data. Others do it by putting all the good stuff behind paywalls. Lichess doesn’t do any of that and never will. Almost 6 years ago, Lichess founder Thibault explained why Lichess is free - and what that means. A lot can change in 6 years but this is one thing that hasn’t and never will.
This is our unbreakable promise to you, our users:
Lichess will never have ads.
Lichess will never sell our user’s data.
Lichess will always be 100% free of charge.
"