Roblox’s customizable server limits appear to have been introduced around April 12, 2023 , when Roblox posted “Server Size, Join Queues and Social Slots Reservations” on the DevForum about experience join improvements and server size customization.

What that means

That 2023 DevForum post is the clearest dated source I found tying Roblox’s server-size customization to an official rollout or announcement. A later DevForum thread in 2025 also reflects that the server size for a single place is controlled through the max player setting in game settings, which fits that earlier feature path.

Important nuance

If you meant private servers instead of the max player limit for a place, those are a different feature entirely and are documented separately by Roblox. If you meant the ability to set a custom player cap in a public experience, the best-supported date is 2023-04-12.

Quick scoop

Feature| Approx. introduction| Source
---|---|---
Customizable server size / join improvements| 2023-04-12| 8
Private servers| documented separately, no same-date match here| 11