Apple

Every Mac runs on macOS, but the system has changed names, version numbers, and designs several times since it first came out in 2001.

Whether you’re trying to see which version your Mac is using, check if it’s eligible for an upgrade, or track down an older release, it’s easier when you can see how everything lines up year by year.

This guide lists every macOS version in order by year, along with its version number, release year, and what changed along the way.

Complete list of macOS versions in order

This table covers every major Mac operating system release, beginning with Mac OS X Cheetah in 2001. Years with no entry are years Apple didn’t release a new version.

The latest macOS version

Right now, the latest version of macOS is macOS Tahoe (version 26.6.1). Apple’s next release, macOS 27 Golden Gate, is in public beta and expected in the fall.

Note: We verified these details in August 2026. Since Apple issues minor updates throughout the year without much fanfare, you can always check your own Mac by opening the Apple menu, then System Settings, then General, then Software Update to see if a newer version has come out since.

How macOS naming has changed over time

If you’ve ever wondered why some older Macs show “Mac OS X” and others show “OS X” or “macOS,” the answer is three separate branding eras, not three different operating systems.

The software started out as Mac OS X, with early versions named after big cats from Cheetah in 2001 through Mountain Lion in 2012. Apple dropped “Mac” from the title with Mountain Lion, then retired the cats altogether the following year, switching to California landmarks starting with Mavericks in 2013.

The current lowercase name, macOS, arrived in 2016 with Sierra. The California names carried over unchanged.

For a long time, the versions followed a standard sequence, moving from the old 10.x system up to version 15. However, in 2025, Apple stopped counting versions and switched to a number tied to the year ahead, bringing all of its devices onto the same one.

That’s why the update following version 15 wasn’t called version 16, but rather macOS 26 Tahoe, matching iOS 26 and other Apple device software. The California names are still here; the system counts by the year now.

Key macOS milestones worth knowing

While every Apple update brings changes, a few releases changed what your Mac can run, what hardware it works with, and how well it holds up. These are the ones that still affect upgrade decisions today.

Mac OS X Cheetah (2001)

Cheetah was the release that moved the Mac to a completely new under-the-hood system built on Unix, which became the starting point for all Mac software that followed. It also brought the Aqua interface, establishing a bright, fluid look that defined Apple’s software design for a generation.

The bigger shift was under the hood. Mac OS X introduced protected memory and preemptive multitasking, making a problem in one app less likely to bring down the entire system. The “X” stood for ten, and Apple kept the 10.x numbering through macOS Catalina in 2019 before Big Sur moved to version 11 in 2020.

macOS High Sierra (2017)

High Sierra didn’t look dramatically different from earlier versions, but it introduced one of the biggest behind-the-scenes improvements in macOS. Apple changed the default way Macs store and organize files by replacing the older HFS+ file system with the newer Apple File System (APFS) on Macs with solid-state drives (SSDs).

APFS also introduced features such as native encryption support, snapshots, faster directory sizing, and copy-on-write protection designed to improve data reliability if a Mac crashes or loses power.

macOS Catalina (2019)

Catalina ended support for 32-bit apps, completing Apple’s transition to 64-bit software. That gave macOS a fully 64-bit app environment, but it also meant older 32-bit apps could no longer run.

This is the line that catches most people. Mojave was the last version that could run 32-bit apps, so if you depend on an older program that was never updated, upgrading past Mojave is what stops it working.

macOS Big Sur (2020)

Big Sur brought a noticeable shift to the Mac. Along with a completely fresh look, it marked a reset in Apple’s software numbering, moving from version 10 to version 11. It was also the first version built to run on Apple’s own processors (M1 chips). This marked the start of a move away from the Intel processors that had run Macs for years.

The update also made it possible to run many iPhone and iPad apps directly on a Mac, as long as it has an Apple chip, making it easier to use the same familiar tools across different devices.

macOS Tahoe (2025)

Tahoe marked the point where Apple switched to a number tied to the year ahead, moving straight from macOS 15 to macOS 26. The number covers the year the version spends most of its life in use, and it keeps the Mac software in step with Apple’s other updates.

Visually, this version brought in a fresh interface style that Apple calls Liquid Glass, drawing the appearance of Mac apps closer to how things look on an iPhone or iPad. It’s also the final stop for Intel-based Macs: Tahoe still runs on them, but macOS 27 onward requires a machine with Apple’s own chips, so Intel owners are now on the last version they’ll get.

How to check which macOS version your Mac is using

If you’re planning to update your Mac, check whether it can run a newer version of macOS, or download an older installer, it’s worth knowing exactly what your Mac is running now.

1. Click the Apple menu in the top-left corner of your screen.
2. Select About This Mac.
   
3. A window opens, showing the macOS name and version number (for example, “macOS Tahoe 26.6.1”). The window looks different depending on which macOS you’re running, but it always shows the name and version.

Which macOS versions are still supported?

As of August 2026, Apple is issuing security updates for macOS Tahoe, macOS Sequoia, and macOS Sonoma.

That’s Apple’s usual pattern, covering the latest version and the previous two, but it isn’t an official policy. In practice, Apple focuses its full security efforts on the absolute newest software, meaning older versions don’t always receive every patch or get them as quickly.

There’s a difference between a Mac that functions and one that Apple still actively protects. A Mac can still run an older operating system for years without issue. The real concern is that as new security flaws are discovered, Apple may no longer fix them on that device.

Software support is tied directly to the model of your Mac, as older hardware eventually loses the ability to run newer macOS software. The year alone doesn’t tell you much: the MacBook Air (M1, 2020) runs macOS Tahoe, while the Intel MacBook Air (Retina, 13-inch, 2020) from the same year doesn’t. If your Mac is able to run a newer operating system, moving up is the best way to benefit from the latest security updates and features.

If your Mac can’t upgrade to a newer supported version, you can still reduce your security risk by being more deliberate about what you download. Try to stay clear of software from websites you don’t know.

How to update or upgrade macOS safely

“Update” and “upgrade” get used interchangeably, but they mean different things. Knowing which one you are about to do changes how you prepare your Mac.

A macOS update is a smaller maintenance step within the same version of the operating system you already have, such as moving from version 26.5.1 to 26.5.2. It’s mostly for fixing bugs, closing security gaps, and keeping things running smoothly.

A macOS upgrade is a bigger transition that moves your Mac to an entirely new generation of software, like shifting from macOS Sequoia to macOS Tahoe. This usually brings a fresh design, changes to your daily apps, and deeper adjustments to how the system works.

Because upgrades change so much, it’s always a good idea to back up your files first, just in case the installation gets interrupted.

When an update or upgrade is available for your Mac, you can install it from System Settings > General > Software Update. Once you start the process, give yourself some time; your Mac will likely restart a few times before it finishes.

If your Mac is getting a bit older, the Software Update window might tell you that you’re already up to date, even if a newer macOS exists. It’s usually best to accept that limit. Getting a newer macOS onto an unsupported Mac means relying on third-party patching tools, which trail behind Apple’s releases and can break when the next update lands.

How to download older macOS versions safely

Apple offers older macOS installers through the App Store and, for the oldest releases, through direct browser downloads. The App Store covers High Sierra 10.13 up to Sequoia 15. For Lion 10.7 through Sierra 10.12, Apple provides disk image files you download in a browser instead. There’s also a Terminal command for anyone comfortable using it, although the versions available depend on what Apple makes available and what’s compatible with the Mac.

Check your Mac’s model and compatibility first. Older macOS versions can only be installed on Mac models that support them.

It’s safest to get these files straight from Apple. Third-party sites and file-sharing networks often host installers that have been altered, which can introduce security issues or fail to install.

The same goes for browser pop-ups that warn you of an immediate security issue; official Apple updates never arrive through a random website advertisement.

If you think you might have accidentally permitted one of these downloads, it’s worth scanning your Mac. Intego ONE for Mac can check your Mac for malicious files or unwanted software picked up that way.

Frequently asked questions

Which macOS version is Apple releasing right now?

The latest version is macOS Tahoe 26, currently on version 26.6.1. Its replacement, macOS 27 Golden Gate, is in public beta and due this fall.

Where do I find my macOS version number?

Go to the Apple menu in the top-left corner of your screen and choose About This Mac. A small window will open showing your system’s name and version number. If you need the exact build number for troubleshooting, just click directly on that version text.

Can I upgrade my Mac to the latest macOS version?

It depends on your Mac model and hardware. The easiest way to find out is to open System Settings > General > Software Update. Here, your Mac will only show you options that work with your device.

How can I download older macOS versions?

If you need an older version of macOS, it’s always best to get it straight from Apple. The App Store carries versions from High Sierra 10.13 up to Sequoia 15, and older releases are available as download files from Apple’s site.

Does each macOS version improve security?

Apple builds new protections into most major upgrades, though some releases bring significant changes while others just patch smaller flaws. Even so, keeping your Mac up to date is the simplest way to get Apple’s latest protections.

Is it safe to install macOS beta versions?

Beta software gives you an early look at what’s coming to the system, but these builds are still unfinished and shouldn’t go on a Mac you rely on every day. It’s best to run them on a separate device where a sudden glitch won’t interrupt your routine.

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