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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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17 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: 47 Votes
17 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
17 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: 14 Votes
17 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
17 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: 9 Votes
17 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
17 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
17 weeks ago
About time. 32 bit apps are insecure, and are a relic from a time long-past.
Rating: 6 Votes
17 weeks ago

What "progress" are you talking about? A bunch of 32-bit haters that don't know WTF they're talking about as usual. 32-bit can phase itself out on its own. There is ZERO reason to make older software (especially games) stop working for no good reason. Apple has been making the OS slower and slower and slower (on purpose probably as they have admitted to doing on the iPhone with batteries and the like) and you guys act like ditching 32-bit is going to make one BIT of difference is a fracking JOKE. You don't know WTF you're talking about and those with 32-bit software resent your attitude as you are part of the PROBLEM and not the solution.



It's not much of a "surprise" that Apple is run by a bunch of money grubbing useless turds (the CEO being first among those, IMO as Apple has been transformed from innovation to follow the leader and stock buybacks). What is a bit surprising is how many casual users actively work against their own best interests. But given the past year, I can't say I'm shocked. At least a third of my own country (possibly 48%) are clearly living in a dream world where forwards is backwards and backwards is forwards.



Right. Then don't run 32-bit apps if it bothers you so damn much! No one is making you! You can see and stop 32-bit apps in Activity Monitor. Have at it. I'm sure it REALLY takes a HUGE amount of ram in a day and age where 16GB of ram is COMMON.

The argument comes down to, "64-bit is a bigger number so clearly 32-bit has to go!" Great argument guys! "But it's a security risk!" Yeah, sure it is. (in Reverso World)

What a bunch of STUPID WORTHLESS ARGUMENTS. My god, no wonder Windows people make fun of Mac users so much. :rolleyes:



Are you having some kind of breakdown? Calm down and keep level-headed, man. People don't listen to arguments when they're being insulted in-between them.

The argument is deeper than you make it out to be. Maintaining 32-bit support requires resources, both for development and testing purposes. Even if you don't have any 32-bit apps running, resources that could've been spent on making a more stable 64-bit system or new features or whatnot, is being spent on patching, maintaining and testing 32-bit libraries on newer systems.
And similar to your argument of "just don't use 32-bit apps if you don't like them" - Just don't update to 10.15 if you need 32-bit support. That'll still give you 4 more years of support, assuming a continuation of support scheme. Or keep both an old system and a new one around on separate hard drives, in a VM, or any number of other solutions. If I may be a bit sarcastic here, you could even keep an older OS on one of your floppy drives :)

Fact is that Apple just doesn't think it's worth the effort to support 32-bit anymore. It's not that it's a benefit to the system really, although in a few minor ways there are benefits too as explained, but the main point is that the resources spent aren't worth the reward. And the broader industry agrees. Ubuntu is killing 32-bit, Nvidia is killing 32-bit, AMD's CEO Dr. Liza Su has said in an interview that she certainly sees why Nvidia did so, and that 32-bit support is consuming a lot of resources, and as a whole, it just doesn't seem to be worth the resources anymore. So little software actually in use is 32-bit anymore, and those who really need legacy apps will have options once it dies.
Rating: 6 Votes
17 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

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