Valve has announced that Steam will officially end support for macOS 11 Big Sur on October 15, 2025. After this date, the Steam client will no longer run on that operating system, and users will need to upgrade to macOS 12 Monterey or later in order to continue using Steam and accessing their games.
The primary reason behind this move is that core features of Steam depend on an embedded version of Google Chrome, which no longer functions reliably on older versions of macOS. Additionally, future versions of the Steam client will require system-level features and security updates that are only available in macOS 12 and above. Without these updates, key components of the platform may not function properly or securely.
macOS Big Sur was introduced in 2020 as the first macOS version to support Apple Silicon chips natively. It marked a major architectural transition for the Mac platform, but Apple officially ended security updates for Big Sur in 2023. That means any system still running macOS 11 today is potentially vulnerable to malware, exploits, and compatibility issues. According to Valve, malware targeting outdated macOS versions can degrade Steam’s performance, cause game crashes, or even lead to stolen account credentials.
Note: Steam for Mac also recently received native support for Apple Silicon Macs.
For Apple Silicon users still on Big Sur, this shift means it is no longer enough to be on Apple’s latest hardware. Upgrading to a newer macOS version is now essential to ensure full compatibility with the Steam client and to maintain a secure gaming environment. Since all Apple Silicon Macs are capable of running macOS 12 or newer, the upgrade path is straightforward for most users.
This update follows Valve’s broader trend of phasing out support for older operating systems. In 2024, Steam ended support for Windows 7, 8, and 8.1. Now, with Big Sur reaching its end of life in the Steam ecosystem, macOS Monterey becomes the new minimum requirement. Users who do not upgrade will lose access not only to the Steam client but also to all games, updates, and account services tied to it.
Valve is strongly encouraging all users on Big Sur to upgrade as soon as possible. While the client may technically run up until October 15, doing so on an unsupported OS poses performance, stability, and security risks. To maintain access to your Steam library and ensure your system is protected, updating to a supported version of macOS is the only option.
