The 64-bit Mac app transition: What you need to know

iMac Pro
iMac Pro (Image credit: iMore)

The Mac has been shipping with 64-bit processors since before the Intel transition and macOS, née OS X, has supported 64-bit for years. Modern technologies, like Metal, require 64-bit. One day, macOS will as well. Apple hasn't said what day that will be, at least not yet, but it's continuing its long, slow march in that general direction.

At WWDC 2018, Apple noted that macOS Mojave will be the last Mac operating system to support 32-bit apps. By fall of 2019, and possibly sooner, any 32-bit apps still on your Mac will no longer work.

Apple has been notifying Mac users since April 2018. If you open an app on your Mac and get an alert that an app isn't optimized, there are a few things you can do.

What notification will Mac users see?

If you're running macOS 10.13.4 or later, starting April 12 at midnight local time, if and when you launch a 32-bit notification, you'll get a notification that says:

[App] is not optimized for your Mac.This app needs to be updated by its developer to improve compatibility.

You'll only ever get the notification once — the first time you launch the 32-bit app, and only to let you know the app will, eventually, be outdated.

Will you still be able to run 32-bit apps on macOS?

Absolutely. For now — and until Apple officially announces and implements an end-of-support date or the next Mac operating system launches, whichever comes first.

Is there a way to see any and all 32-bit apps you might have installed on your Mac?

There is, but it's tedious.

  1. Click on the Apple icon in the Menubar.
  2. Click on About this Mac.
  3. Click on System Report.
  4. Click on Applications (under Software.)
  5. Click on an App.
  6. If the 64-bit (Intel) field says No, the app is 32-bit.

What do you do if you have 32-bit apps?

Check the Mac App Store or developer's webpage for an updated, 64-bit version of the app. If one's available, upgrade.

If there's no 64-bit version available, you can send the developer feedback, or you can look for a similar app that does support 64-bit.

When will the 32- to 64-bit transition be complete?

Apple hasn't set that date yet. Hopefully, the company is watching how fast developers are moving and users are updating and, when it does set a date, it'll be one that works for as many people as possible. The only thing we know so far is that Apple has confirmed that macOS 10.14 Mojave wil be the last macOS to support 32-bit apps.

For more information, keep an eye on Apple's knowledge base (opens in new tab).

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Rene Ritchie

Rene Ritchie is one of the most respected Apple analysts in the business, reaching a combined audience of over 40 million readers a month. His YouTube channel, Vector, has over 90 thousand subscribers and 14 million views and his podcasts, including Debug, have been downloaded over 20 million times. He also regularly co-hosts MacBreak Weekly for the TWiT network and co-hosted CES Live! and Talk Mobile. Based in Montreal, Rene is a former director of product marketing, web developer, and graphic designer. He's authored several books and appeared on numerous television and radio segments to discuss Apple and the technology industry. When not working, he likes to cook, grapple, and spend time with his friends and family.

  • “If you're running macOS 10.13.4 or later, starting April 12 at midnight local time, if and when you launch a 32-bit notification, “ Fortunately, I don’t launch any 32 bit notifications.
  • 32-bit notifications. Even though it's a copy error, it's still quite funny
  • Kudos to the way Apple are handling this, although I'm sure folks will still whinge and whine in a few years time when the ten year old piece of software their using stops working properly.
  • I never understand this mindset, why do people expect old software to work forever? 90% of the time there is better software out there if your current piece of software is not supported. If you're really insistent on using old software, then you will need an old computer/OS to go with it. A MacBook Pro with Touch Bar doesn't have a slot for floppy disks in the same way that a future version of macOS won't have a "slot" for 32-bit applications
  • Oh **** it.
    The version of Garageband I use is 32bit. I've been fighting off updating as the ducking features I use are not on the current version.
    I only hope that this amnesty lasts, or I downgrade to a previous version of macOS.
  • What features are missing? I'm fairly new to this brilliant slice of software fried gold and and have only used the 64bit version.
  • I want iOS apps on my Mac!!!
  • They've been doing this already for MONTHs. Not news.
  • This article was bumped, you can see there are comments on this from April
  • it's almost the last mac OS period...
    zdnet says wwdc for more like a funeral for macOS than anything else.
    of course apple fanboys can't see past the reality distortion to see it clearly.
  • To be fair that article says more that Macs are slowly being phased out in preparation for the next big thing. It's important to recognise that Macs won't be going anywhere until something can justify replacing them, for example the iPad can't replace the Mac yet because at least in terms of developer applications it's incredibly lacklustre, heck it doesn't even have all of Apple's development applications. It's almost like you think the last macOS period is a bad thing. Products evolve, as long as what it's evolving to is better (which it will be before Macs are put to rest), then there's no problem at all.
  • And you choose to believe what some writer wrote on ZDNET, that bastion of misinformation?