Valve Corporation has announced that, effective October 15, 2025, its Steam gaming platform will no longer support macOS 11 Big Sur. This decision necessitates that Mac users upgrade to macOS 12 Monterey or later to continue accessing Steam and its associated services.
The primary reason for this change is Steam’s reliance on an embedded version of Google Chrome, which has ceased to function properly on older macOS versions. Future updates to the Steam client will also require security features and system capabilities that are only available in macOS 12 and subsequent releases.
Apple discontinued security updates and technical support for macOS 11 Big Sur in 2023. Consequently, systems running this version are more susceptible to malware and other security vulnerabilities. Valve strongly recommends that users upgrade their operating systems before the October deadline to ensure the security and optimal performance of their systems, as well as to maintain access to their Steam accounts and game libraries.
This move aligns with Valve’s ongoing efforts to enhance the Steam experience on macOS. In June 2025, the company released a beta version of the Steam client with native support for Apple Silicon, signaling a commitment to optimizing performance on newer Mac hardware.
For users still operating on macOS 11 Big Sur, it’s crucial to plan for an upgrade to macOS 12 or later before October 15 to avoid disruptions in accessing Steam and its services.
