The Steam gaming store will drop all support for the last versions of macOS that could still run 32-bit games. Valve has announced that it will drop Steam support for macOS High Sierra and macOS Mojave in early 2024.
Valve said that as of February 15, 2024, existing Steam Client installations on the above operating systems will no longer receive updates of any kind from Steam. This includes security updates. Technical support for issues related to macOS 10.13 (High Sierra) and 10.14 (Mojave) will not be available.
Valve announced the change in a Steam support post:
Unfortunately, macOS 10.14 was the last version to support running 32-bit games on macOS. Apple chose to drop support for 32-bit applications in macOS 10.15 (released 2019), and since many developers have not updated their games to support 64-bit executables, some games will effectively stop functioning on macOS.
The Steam store will stop considering games that offer only 32-bit macOS binaries to be Mac compatible at the end of 2023. 98%+ of Steam customers on Mac are already running macOS 10.15 or newer. This means 32-bit only games and applications no longer run on your current operating system.
As noted by ArsTechnica, Valve’s move is related to Google’s ending of Chrome support for macOS 10.13 and 10.14, several parts of which the Steam UI relies on.
Valve says it says it expects “the Steam client and games on these older operating systems to continue running for some time.”
