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

Wednesday January 24, 2018 11:25 am PST by Juli Clover

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.

macoshighsierra
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 Forum: macOS High Sierra

Popular Stories

Apple Rumored to Announce New Product on February 19

Thursday February 5, 2026 12:22 pm PST by Joe Rossignol

Apple plans to announce the iPhone 17e on Thursday, February 19, according to Macwelt, the German equivalent of Macworld. The report, citing industry sources, is available in English on Macworld. Apple announced the iPhone 16e on Wednesday, February 19 last year, so the iPhone 17e would be unveiled exactly one year later if this rumor is accurate. It is quite uncommon for Apple to unveil...

Apple Shows Off a Key Reason to Upgrade to the iPhone 17

Saturday February 7, 2026 9:26 am PST by Joe Rossignol

Apple today shared an ad that shows how the upgraded Center Stage front camera on the latest iPhones improves the process of taking a group selfie. "Watch how the new front facing camera on iPhone 17 Pro takes group selfies that automatically expand and rotate as more people come into frame," says Apple. While the ad is focused on the iPhone 17 Pro and iPhone 17 Pro Max, the regular iPhone...

• 79 comments

Tim Cook Teases Plans for Apple's Upcoming 50th Anniversary

Thursday February 5, 2026 12:54 pm PST by Joe Rossignol

Apple turns 50 this year, and its CEO Tim Cook has promised to celebrate the milestone. The big day falls on April 1, 2026. "I've been unusually reflective lately about Apple because we have been working on what do we do to mark this moment," Cook told employees today, according to Bloomberg's Mark Gurman. "When you really stop and pause and think about the last 50 years, it makes your heart ...

• 149 comments

Why Apple's iOS 26.4 Siri Upgrade Will Be Bigger Than Originally Promised

Friday February 6, 2026 3:06 pm PST by Juli Clover

In the iOS 26.4 update that's coming this spring, Apple will introduce a new version of Siri that's going to overhaul how we interact with the personal assistant and what it's able to do. The iOS 26.4 version of Siri won't work like ChatGPT or Claude, but it will rely on large language models (LLMs) and has been updated from the ground up. Upgraded Architecture The next-generation...

• 155 comments

iOS 26.3 and iOS 26.4 Will Add These New Features to Your iPhone

Tuesday February 3, 2026 7:47 am PST by Joe Rossignol

While the iOS 26.3 Release Candidate is now available ahead of a public release, the first iOS 26.4 beta is likely still at least a week away. Following beta testing, iOS 26.4 will likely be released to the general public in March or April. Below, we have recapped known or rumored iOS 26.3 and iOS 26.4 features so far. iOS 26.3 iPhone to Android Transfer Tool iOS 26.3 makes it easier...

• 37 comments

Top Rated Comments

casperes1996

105 months 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

Score: 47 Votes (Like | Disagree)

zorinlynx

105 months 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.

Score: 39 Votes (Like | Disagree)

pgiguere1

105 months 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.

Score: 14 Votes (Like | Disagree)

keysofanxiety

105 months 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.

Score: 9 Votes (Like | Disagree)

Guy Clark

105 months 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.

Score: 9 Votes (Like | Disagree)