Is KeePassium free?

Yes.

Free as in freedom (libre):

KeePassium is free open source software available under the GPL license.

Free as in free beer (gratis):

You don't have to pay to use KeePassium. We do offer a paid version with premium features for experts and business users, but free version is fully functional for most people.

Why the paid version?

Improving and maintaining KeePassium is an ongoing process. Software is never "done": every year there is a new iPhone running new iOS, new possibilities, new expectations. Answering a support email might take a minute or an hour — but someone has to be on guard the whole day, every day. Just like your local fire brigade or system administrator.

Premium version ensures that KeePassium remains fresh and shiny over the years.