The state parliamentary year has ended with legislation for a sex offender register passing the lower house.

The bill includes plans to establish a website which would include some details of known sex offenders.

Western Australian authorities already monitor the movements of such offenders but the new legislation would allow the public to track the names and images of serious or repeat offenders in their suburb through a police website.

The Police Minister Rob Johnson says parents or guardians will be able to lodge an online inquiry with police if they suspect a person in contact with their child is a reportable sex offender.

"They will be furnished with a photograph of that sex offender that lives within those postcode areas and that means that the parents can then keep a watchout for that person and make sure that their children make no contact with them," he said.

Mr Johnson thanked the Opposition for its support.

"The public will see this as an achievement for the Legislative Assembly in general for the Labor and Liberal parties to be supportive of legislation that is designed to protect the safety and sexual safety of children," he said.

The bill will be debated in the upper house next year.