Like the PlayStation 4, Xbox One will support up to eight users in its party chat at once. This is the same number as the Xbox 360 party chat supported as well.
Microsoft previously confirmed that Xbox One users can also have up to 1,000 friends on their account, up from the 100 supported on Xbox 360. Unfortunately, the Xbox One will not recognize real names at launch, though Microsoft may revisit this feature in the future. The PS4, meanwhile, will support 2,000 friends and will recognize real names at launch.