Overview

• Support for Steam on macOS 11 Big Sur will cease on October 15, 2025, after which the client and any purchased games will fail to launch on that OS.
• Steam’s core features depend on an embedded Chromium framework that no longer functions on Big Sur’s older system, necessitating the cutoff.
• Valve strongly urges macOS 11 users to update sooner rather than later to avoid service disruptions and exposure to unpatched vulnerabilities.
• Future Steam updates will require macOS 12 or newer to leverage essential security patches and system features absent in Big Sur.
• Following WWDC 25, Valve released a beta of its native Apple Silicon Steam client to prepare for diminishing Rosetta 2 support.