Meta has agreed to an about US$18 billion ($25 billion) settlement to resolve claims brought by 29 state attorneys general that it intentionally designed addictive platforms that harmed young people’s mental health, according to a court filing Wednesday.

The settlement ends a landmark legal battle for the social media giant.

As part of the settlement, Meta has agreed to make changes to its platforms, such as establishing daily time limits for teen users, the filing states.

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It comes just over a week after a trial began in California, in which four of the states were seeking as much as US$1.4 trillion (A$1.9 trillion) in damages and changes to the company’s platforms.

Instagram head Adam Mosseri was set to take the stand for a second day on Wednesday, and Meta CEO Mark Zuckerberg was also expected to testify in the case.

Meta has long denied that its platforms harm children and had called the states’ claims “unsubstantiated.” Meta did not admit wrongdoing as part of the settlement.

“Ensuring teens have a safe and productive experience on our platforms is an absolute imperative for Meta,” the company said in a blog post about the agreement on Wednesday.

“We want to get this right for parents and teens, and that’s why we partnered with state attorneys general to set a new industry standard.”