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.

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

iPhone SE 4 Vertical Camera Feature

iPhone SE 4 Production Will Reportedly Begin Ramping Up in October

Tuesday July 23, 2024 2:00 pm PDT by
Following nearly two years of rumors about a fourth-generation iPhone SE, The Information today reported that Apple suppliers are finally planning to begin ramping up mass production of the device in October of this year. If accurate, that timeframe would mean that the next iPhone SE would not be announced alongside the iPhone 16 series in September, as expected. Instead, the report...
iPhone 17 Plus Feature

iPhone 17 Lineup Specs Detail Display Upgrade and New High-End Model

Monday July 22, 2024 4:33 am PDT by
Key details about the overall specifications of the iPhone 17 lineup have been shared by the leaker known as "Ice Universe," clarifying several important aspects of next year's devices. Reports in recent months have converged in agreement that Apple will discontinue the "Plus" iPhone model in 2025 while introducing an all-new iPhone 17 "Slim" model as an even more high-end option sitting...
Generic iPhone 17 Feature With Full Width Dynamic Island

Kuo: Ultra-Thin iPhone 17 to Feature A19 Chip, Single Rear Camera, Semi-Titanium Frame, and More

Wednesday July 24, 2024 9:06 am PDT by
Apple supply chain analyst Ming-Chi Kuo today shared alleged specifications for a new ultra-thin iPhone 17 model rumored to launch next year. Kuo expects the device to be equipped with a 6.6-inch display with a current-size Dynamic Island, a standard A19 chip rather than an A19 Pro chip, a single rear camera, and an Apple-designed 5G chip. He also expects the device to have a...
iPhone 16 Pro Sizes Feature

iPhone 16 Series Is Less Than Two Months Away: Everything We Know

Thursday July 25, 2024 5:43 am PDT by
Apple typically releases its new iPhone series around mid-September, which means we are about two months out from the launch of the iPhone 16. Like the iPhone 15 series, this year's lineup is expected to stick with four models – iPhone 16, iPhone 16 Plus, iPhone 16 Pro, and iPhone 16 Pro Max – although there are plenty of design differences and new features to take into account. To bring ...
icloud private relay outage

iCloud Private Relay Experiencing Outage

Thursday July 25, 2024 3:18 pm PDT by
Apple’s iCloud Private Relay service is down for some users, according to Apple’s System Status page. Apple says that the iCloud Private Relay service may be slow or unavailable. The outage started at 2:34 p.m. Eastern Time, but it does not appear to be affecting all iCloud users. Some impacted users are unable to browse the web without turning iCloud Private Relay off, while others are...

Top Rated Comments

casperes1996 Avatar
85 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 Avatar
85 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 Avatar
85 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 Avatar
85 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 Avatar
85 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)
arrowood Avatar
85 months ago


;-) Ok, ok, yeah. I get it. 32-bit overhead, memory, libraries, etc. But, but, I can't live without Adobe Fireworks ;-)
Score: 8 Votes (Like | Disagree)