upgrading from 10.14.6 to 14.4.1

You can migrate using an external drive with a USB interface. No need to directly connect the two Macs.

Make a current backup of the old machine onto the drive. This can be either a Time Machine backup, or a bootable clone backup (made with Carbon Copy Cloner or with SuperDuper!). Then transfer the drive to the new Mac (might require the use of a USB-C to USB-A adapter) and point Migration Assistant at the drive.

macOS 10.13 High Sierra and macOS 10.14 Mojave support 32-bit apps but later macOS like macOS 14 Sonoma do not. So make sure you don't rely using such old 32-bit apps anymore.

One option to test that is to make a bootable clone to an external disk with Carbon Copy Cloner. Then upgrade that to macOS 14 Sonoma, use it for a few days and check that all your mission critical apps still work.

Then upgrade also the internal disk and continue making backups from it.

A new Mac should come with current, or almost-current, versions of those three applications.

I'd hope that Migration Assistant would be smart enough not to overwrite the versions pre-installed on your new Mac with the ones from your backup of your High Sierra machine.

Apple's Pages, Numbers, and Keynote will not convert by upgrading the operating system to macOS Sonoma 14.4.1 or later as they are not in the operating system build. Those applications will need to be manually updated from the Mac App Store to their current versions of 14.0.

Apple's Ink/Ink Server was retired a few years back.

Apple has support communities for Pages, Numbers, and Keynote.

If you're going from an Intel-based Mac running High Sierra to an Apple-Silicon-based one running Sonoma, then

• 32-bit applications won't work on the new machine
• Neither will Intel-only kernel extensions of any sort (e.g., device drivers). Rosetta 2 can translate many 64-bit macOS/Intel applications, but it can't translate system-level code.

If you are running Windows as a second operating system on your Intel-based MacBook Pro, be aware that Apple-Silicon-based Macs don't support Boot Camp, and can't run Intel-based versions of Windows – only ARM-based versions.

New machines won't come with iTunes, because Catalina split its functions among (Music / TV / Podcasts / Books) and the Finder.

As Matti pointed out, Catalina through current (Sonoma) operating systems do not support 32-bit applications, or printer/scanner drivers. On Mojave, before you perform an upgrade, run the free Go64 application which will show all 32-bit software and libraries. That may be an eye opener and if there are any show-stoppers, check with the application vendors to see if they provide current (64-bit) applications compatible with macOS 14.4.1.

You would want to thoroughly remove any anti-virus or so-called Mac "cleaner" applications prior to the upgrade. Any application that installed kernel extensions on Mojave should also be thoroughly removed per vendor instructions.

You will want a final Time Machine backup and then eject that drive before the upgrade. Use a new external drive formatted as APFS for Time Machine backups on macOS Sonoma.

If you are using Microsoft Office on Mojave, you will need new Microsoft software and licensing for Sonoma as Microsoft only supports new Office installs on macOS versions (12, 13, and 14). That software must be currently licensed releases of Microsoft 365 or Office 2021 for Mac.

Migrating data to the newer machine is going to pose a challenge.

A thunderbolt 2 to 3 adapter may work together with a thunderbolt 2 to Firewire 800 adapter and a Firewire 800 cable.

If it doesn't just a straight ethernet cable between the two machines will work better with a thunderbolt-3/USB-C ethernet adapter on the new machine.

Then the Migration Assistant on the old machine and Setup assistant on the new machine will allow brining over only 64 bit applications. 32 bit applications and drivers won't work. Selectively bringing over what you know works best, and you can just do Documents and Settings, and then see what applications are 64 bit and install them new on the new Mac.

https://roaringapps.com/

is a great place to find what versions are compatible with Catalina and later for good compatibility, and Apple Silicon for best compatibility.

Windows ARM is needed with Parallels or VMWare on the new machine in place of Boot Camp on the older Mac.

Printer/Scanner drivers may work if you used AirPrint compatible printer with. the Option key when you add the printer, as long as they are on the same WiFi network. Otherwise check for the same compatibility on the printer manufacturer website for Catalina or later.

An external DVD drive is needed for any old CDs or DVDs.

Your external hard drive running the older OS will not be able to boot the newer machine, until you upgrade its operating system to be the same as the newer machine.

Firewire is not able to boot newer computers. It is best to adapt any hard drives to USB if possible. If you have a Firewire hard drive case, there are many USB-SATA adapters for old hard drives that can come useful. Do not move them out yourself unless you are acquainted with the anti-static routines for opening drive cases. Consult with an authorized service provider in person to ensure you don't mess yourself up.

One more thing: macOS 10.13 High Sierra supported both MacOS Extended and APFS. But later macOS supports only APFS and it is VERY slow when booted from a spinning HDD so booting from SSD (internal or external) is recommended. (I guess you updating from macOS 10.13.6 High Sierra, and 10.14.6 Mojave in the headline is a typo??).

> I'm guessing I can put a bootable clone on a flash drive?

USB thumb drives do work but they are usually slow and not so reliable as proper SSDs. So "flash drives" are not recommended for boot drives.