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macOS High Sierra 10.13.4 Displays Warnings When Opening 32-Bit Apps as Part of Apple's Phase Out Plan

Starting with macOS High Sierra 10.13.4, Apple is commencing with its plan to begin phasing out 32-bit apps on Macs. Apple has promised that macOS High Sierra will be the "last macOS release to support 32-bit apps without compromises."

After installing macOS High Sierra 10.13.4, which is now available in a beta testing capacity, when you open up an app that's a 32-bit app, you'll get a warning about its future incompatibility with the macOS operating system.


This is the first of many warnings Apple plans to provide as it works to put an end to 32-bit Mac apps, and this initial warning will only be shown one time for each app.

Apple's efforts to phase out 32-bit apps on Macs mirror the path it took when ending 32-bit app support on iOS devices. In iOS 10, Apple provided increasingly more insistent warnings to let users know that their apps wouldn't work with future versions of iOS before phasing out 32-bit support entirely in iOS 11.

As of January 2018, all new apps submitted to the Mac App Store must be 64-bit, and all apps and app updates submitted must be 64-bit by June of 2018. The next version of macOS after High Sierra will include "aggressive" warnings about 32-bit apps before they are phased out entirely.

Once 32-bit apps are phased out on Macs, they won't be able to be used at all, so users will need to find replacements for older 32-bit apps that aren't likely to be updated to 64-bit.

Related Roundup: macOS High Sierra


Top Rated Comments

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4 weeks ago

The CPU has NO PROBLEM executing 32-bit code, and there isn't even a performance hit in doing so. There's no real solid reason to discontinue 32-bit support. This is going to keep people who requires certain older apps from upgrading to the latest version of MacOS, and expose them to security vulnerabilities for no good reason at all.



Running 32-bit code, means that you need to keep a 32-bit version of all the libraries and frameworks those apps may rely on. That's both storage, and more crucially RAM consuming. And there is in fact a performance hit to having 32-bit and 64-bit apps running on the same system, as opposed to if both were 64-bit. If they are both 64-bits they can share certain conditions giving the processor an ability to preemtptively execute that code more quickly.

32-bit support isn't free either. You need to test against your 32-bit libraries and if you update a 64-bit library for a security reason, you'll also need to update and test the corresponding 32-bit library. And it may behave differently.

Nvidia has stopped supporting 32-bit systems because the testing burden just got too big. A lot of Linux distros are killing 32-bit variants as well.

It's not worth the effort anymore.

Edited slightly to fix a typo and improve readability
Rating: 45 Votes
4 weeks ago
I wonder why Apple has such a fetish for phasing out 32-bit code.

The CPU has NO PROBLEM executing 32-bit code, and there isn't even a performance hit in doing so. There's no real solid reason to discontinue 32-bit support. This is going to keep people who requires certain older apps from upgrading to the latest version of MacOS, and expose them to security vulnerabilities for no good reason at all.
Rating: 39 Votes
4 weeks ago

I wonder why Apple has such a fetish for phasing out 32-bit code.

The CPU has NO PROBLEM executing 32-bit code, and there isn't even a performance hit in doing so. There's no real solid reason to discontinue 32-bit support. This is going to keep people who requires certain older apps from upgrading to the latest version of MacOS, and expose them to security vulnerabilities for no good reason at all.


The performance hit comes from the OS having to keep both a 32-bit and 64-bit version of shared libraries in RAM.
Rating: 13 Votes
4 weeks ago

Thankfully Apple has kept 32-bit support for longer on MacOS so fewer apps are affected, but I can still see users refusing to update to the next MacOS because their useful older software is going to break.

Just keep using Snow Leopard complete 32-bit support and Rosetta for PPC apps plus pre iOS infestation.
Rating: 9 Votes
4 weeks ago


;-) Ok, ok, yeah. I get it. 32-bit overhead, memory, libraries, etc. But, but, I can't live without Adobe Fireworks ;-)
Rating: 8 Votes
4 weeks ago

I wonder why Apple has such a fetish for phasing out 32-bit code.

The CPU has NO PROBLEM executing 32-bit code, and there isn't even a performance hit in doing so. There's no real solid reason to discontinue 32-bit support. This is going to keep people who requires certain older apps from upgrading to the latest version of MacOS, and expose them to security vulnerabilities for no good reason at all.


People said the same thing when they went from 16 bit to 32 bit. Honestly, they did. Stubbornness for change is just slowing down progress. Just look at the cluster that is Windows which still rocks Program Files x86 for legacy purposes.

Apple have always been happy to drop older standards. 32 bit is only the latest in a long list. They did this in iOS and they’ve already dropped 32 bit support/plug-ins years ago for their Pro Apps (LPX), so this shouldn’t come as much surprise.
Rating: 8 Votes
4 weeks ago
About time. 32 bit apps are insecure, and are a relic from a time long-past.
Rating: 6 Votes
4 weeks ago

Just keep using Snow Leopard complete 32-bit support and Rosetta for PPC apps plus pre iOS infestation.


In my opinion, best and favourite OS.
Rating: 6 Votes
4 weeks ago
I fully expect half my games library to stop working when 32-bit support ends. Heck, Steam is still 32-bit. Valve better not take Valve Time updating it. Sad times.
Rating: 5 Votes
4 weeks ago

You're not wrong but why hold on to the past? That is Apples motto. They dropped 32-bit on the iPhone for the ARM reason I described, logically it makes sense for them to do the same on Macs.

Cause some stuff doesn't get updated ever, especially games. I play games rarely and almost never buy new ones (else I'd use Windows lol), and it really sucks updating my OS and finding that my favorite game no longer works. Many games have no replacement, like Rome Total War (RTW 2 sucks). So I'm afraid to update, and I'm sure many are in the same boat, but I'm also aware of the security risks of staying outdated while others are not.

From my selfish perspective, the update isn't worth it if my software breaks. I agree it sets a bad precedent to provide kernel-level backwards compatibility that far, but I'd really appreciate an emulator running in userspace.
[doublepost=1516838307][/doublepost]

10.13.4 appears to bring official eGPU support! This is much bigger news than warnings about 32-bit apps. New AMD GPUs are now correctly identified in About This Mac and System Information including:
-Radeon RX 580
-Radeon Pro WX 7100
-Radeon Pro WX 5100
-Radeon RX 570
-Radeon RX 480
-Radeon RX 470
-Radeon Pro WX 4100
-Radeon RX 460
-Radeon RX 560
-Radeon RX 550
-Radeon Pro WX 9100
-Radeon Vega Frontier Edition
-Radeon RX Vega 64
-Radeon RX Vega 56

Now if only we could find those cards in stock at a reasonable price. :)

Yeah, good luck. RX580 was like $270 before Christmas, and I didn't buy it. Huge mistake. Now all these ******s are mining ethereum with it, so it's at least $500.
Rating: 4 Votes

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