I realize the next version beyond Mojave macOS may enforce a 64-bit application restriction. Is there potentially something about the 64-bit Steam Client for the current Mojave macOS 10.14 that could prevent playing 32-bit games distributed and/or installed through it?

For example: this older bundle of games with OS X versions that appear to run on macOS 10.13, despite their requirements sections each listing a more limited version range.

Most of the digging I've done indicates games like the examples above will be playable but I wanted to be sure I'm not missing something about the Steamworks SDK, its Custom Executable Generation (CEG) or a some other detail.

I've never seen Valve, game developers or technical resources plainly answer this particular question, though this comment that doesn't mention macOS specifically indicates it should be fine. Other reading points me in that direction but I'm looking for something definitive.

I also understand that:

  • 1
    I see no reason why the 64-bit Steamclient would fail to launch another 32-bit game application. There might be problems though in the Steam Overlay Integration.
    – DrFish
    Commented Dec 5, 2019 at 8:22

1 Answer 1


According to Apple’s own support document about 32-bit compatibility I see no reason why 32-bit apps should stop working with macOS 10.14.

Can I keep using my 32-bit apps?

Yes, you may continue to use 32-bit apps with your Mac today. Using 32-bit software has no adverse effects on your data or your computer.

The document also mentions that Mojave will be the last macOS version to support 32-bit apps, though.

At our Worldwide Developers Conference in 2018, Apple informed developers that macOS Mojave is the last version of macOS to run 32-bit apps.

  • My question is aimed to determine if 64-bit Steam Client on Mojave (or even earlier macOS versions) will break or interfere with the playability of the 32-bit games the Steam Client manages. I've edited my question to reinforce my prior awareness that 32-bit apps, in general, work on Mojave.
    – jmmygoggle
    Commented Nov 10, 2018 at 0:54
  • The steam client shouldn't interfere with the apps themselves. As long as the MacOS/MacOSX version supports both 32 and 64 bit programs there shouldn't be an issue. Steam's client can manage any executable you'd like in fact, it doesn't really do much other than put the overlay on and do some DRM checks when you launch certain titles. A 64 bit client will not prevent a 32 bit program from being launched through it. Commented Feb 26, 2020 at 15:22

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