Valve Corporation has announced that, effective October 15, 2025, the Steam Client will no longer function on Macs running macOS 11 Big Sur. This decision stems from compatibility issues with the embedded version of Google Chrome utilized by Steam, which no longer operates on older macOS versions. Future iterations of Steam will necessitate features and security updates available only in macOS 12 and subsequent versions.
For users still operating on macOS 11, this means that Steam and any associated games or content will become inaccessible unless the operating system is updated. Valve emphasizes the importance of upgrading, noting that Apple ceased security updates and technical support for macOS 11 in 2023. Continuing to use this outdated system exposes computers to potential malware and exploits, which can degrade performance, cause crashes, and compromise sensitive information, including Steam account credentials.
This move aligns with Valve’s broader strategy to transition Steam for Mac into a native Apple Silicon application, following the phasing out of Rosetta 2. The company released the first native beta shortly after WWDC25, aiming to enhance performance and compatibility with newer Mac hardware.
