You’ve got an old Mac sitting in the corner, maybe a 2011 MacBook Pro or a Late 2009 iMac, and it's basically a paperweight right now. It feels sluggish. The apps won't open. You're thinking about a trip to the recycling center, but honestly, there's still life in that aluminum shell if you know how to handle the update to os high sierra.
High Sierra (macOS 10.13) is kinda the "end of the road" for a massive generation of Intel Macs. It’s that weird, transitional middle ground where Apple introduced the APFS file system but hadn't yet killed off 32-bit app support. If you're trying to resurrect an old machine for a kid, a garage workstation, or just a dedicated distraction-free writing tool, this is the version you’re likely looking at. But man, doing this in 2026 is a lot more annoying than it used to be.
Why High Sierra still matters in 2026
Most people think "newer is better," and usually, they're right. But for specific hardware, High Sierra is the sweet spot. If you go much further—say, trying to force Mojave or Catalina onto a machine that doesn't natively support it—you lose Metal graphics acceleration. Everything gets laggy. The windows stutter. It's a mess.
High Sierra is the last stop for many Macs that still have "guts." It’s stable. It’s the final version to support a huge library of legacy software that died when Apple went all-in on 64-bit with Catalina. If you have an old copy of Adobe CS6 or some ancient MIDI software that you refuse to pay a subscription for, High Sierra is your sanctuary.
The "Expired Certificate" nightmare
Here is a specific detail that trips up almost everyone: the installer might tell you it's "damaged" or "cannot be verified." It’s not actually damaged. It’s just that the security certificate inside the installer expired years ago. To fix this, you literally have to trick your Mac into thinking it's 2018.
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Open the Terminal while in the installer environment and type date 0101010118. That sets the clock to January 1st, 2018. Suddenly, the "damaged" installer works perfectly. It feels like a weird hacker movie trope, but it’s the only way to get the job done on some machines.
Can your Mac actually handle the update?
Apple was surprisingly generous with the system requirements for this one. Basically, if your Mac was made between 2009 and 2017, you’re probably in the clear. Specifically:
- MacBook: Late 2009 or newer.
- MacBook Air/Pro: Mid 2010 or newer.
- iMac: Late 2009 or newer.
- Mac Mini: Mid 2010 or newer.
- Mac Pro: Mid 2010 or newer.
You only need 2GB of RAM to "run" it, but let’s be real—if you don't have at least 4GB (and preferably 8GB), it’s going to be a painful experience. High Sierra loves an SSD. If you’re still running an old spinning hard drive, this update will force a conversion to the APFS file system, which is optimized for flash storage. On an old HDD, APFS can sometimes make things feel even slower than before.
How to actually get the installer now
You can't just search the App Store for "High Sierra" and expect it to pop up. Apple has hidden the listing. You need the direct link.
The most reliable way is to use a Safari browser (Chrome often breaks these links) to visit the official Apple Support page for "How to download and install macOS." They maintain a list of hidden App Store links there. Once you click it, the App Store will magically open to the High Sierra page.
Creating a bootable drive (The pro move)
Don't just run the installer from your Applications folder. It fails half the time on older OS versions. You want a 16GB USB stick and a little bit of Terminal courage.
- Download the installer (don't let it start).
- Plug in your USB drive (name it
MyVolume). - Paste this into Terminal:
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume - Hit Enter, type your password, and wait.
Now you have a physical "rescue disk" that can wipe your Mac and do a clean update to os high sierra without dragging along a decade of digital junk.
The APFS complication you didn't ask for
When you install High Sierra on a Mac with an SSD, it will convert your drive to APFS. There is no checkbox to opt-out. For 99% of people, this is great. It's faster and more secure.
But if you’re a power user who needs to share that drive with even older Macs (running El Capitan or Sierra), those older machines won't be able to read the drive anymore. APFS is a "one-way street." Once you go there, you aren't going back to HFS+ without a total wipe.
Is it safe to be online with 10.13?
Honestly? It's risky.
Apple stopped pushing security patches for High Sierra in late 2020. That means vulnerabilities found in the last five years are wide open on your machine. If you’re using this Mac for banking or sensitive work, you’re asking for trouble.
However, if you're just using it for creative work, offline tasks, or browsing "safe" corners of the web, you can mitigate the risk. Stop using Safari immediately. It hasn't been updated for High Sierra in years and many websites will look broken. Use Firefox ESR (Extended Support Release) or Legacy-vlc browsers. They still provide some level of security and compatibility for older systems.
Actionable steps to revitalize your machine
Don't just click "update" and hope for the best. Follow this sequence if you want the Mac to actually be usable:
- Max out the RAM: If your Mac allows physical RAM upgrades (pre-2013 models), go to 8GB or 16GB. It costs thirty bucks on eBay and makes a bigger difference than the OS itself.
- Swap the HDD for an SSD: If you still hear a "whirring" sound inside your Mac, that's your bottleneck. A cheap SATA SSD will make High Sierra feel like a brand-new computer.
- Clean the Dust: While you're in there, blow out the fans. High Sierra pushes the CPU harder than older versions, and thermal throttling will kill your performance.
- Use OpenCore Legacy Patcher (Optional): If you finish the High Sierra update and realize your Mac is still "too old" for the apps you need, look into OCLP. It can technically push many of these machines all the way to macOS Sonoma or Sequoia, though it requires a bit more technical tinkering.
The update to os high sierra isn't just a software patch; it's a way to keep hardware out of the landfill. It’s not perfect, and the web browsing experience is getting clunky, but as a dedicated machine for music, writing, or local file storage, it’s still a powerhouse. Just remember to set that clock back if the installer throws a tantrum.