OpenCore Legacy Patcher: a newer macOS on an old Mac?

OpenCore Legacy Patcher is a free program that installs a newer version of macOS on an older Intel Mac that Apple officially no longer supports. That way, for example, a 2015 MacBook Pro gets a more recent macOS than Apple offers it. Sounds attractive, but there are catches. This article explains what OpenCore Legacy Patcher does, which Macs it works on and what to watch out for.

Blue Apple repairs MacBooks in Amsterdam and regularly sees older Macs come in after such an installation, sometimes because something stopped working. So we list the pros and cons.

What does OpenCore Legacy Patcher do?

The program is made by a group of volunteers (Dortania) and is open source. It places its own boot layer in front of macOS. That makes the Mac believe it is a newer model, so the installation of a newer macOS goes ahead. The program then adjusts parts of the system ("root patches") so components such as the graphics chip and Wi-Fi keep working.

Which Macs does it work on?

• Intel Macs only. Macs with an Apple chip do not need it: they simply get the latest macOS. macOS 27 Golden Gate only runs on Apple chips, so the patcher is mainly meant for Intel Macs that got stuck on an older version.
• Not every macOS version. Which versions the patcher supports changes with every new release. Check the project's site for what applies to your model and the version you want, and read the known issues.
• The older, the more limits. On very old Macs graphics acceleration sometimes does not work well, which makes everything feel slow.

The risks

1. No support from Apple. If something goes wrong, Apple will not help you with the software.
2. Updates can break things. After a macOS update you sometimes have to run the patcher again. Forget it, and Wi-Fi or graphics may suddenly stop working.
3. Security. For the patches some macOS protections are switched off. In theory that makes the Mac more vulnerable.
4. Your data. If it fails halfway, the Mac may not start up any more. Without a backup you can lose files.

How to approach it sensibly

1. Make a full Time Machine backup to an external drive.
2. Read on the project's site which features do not work on your model.
3. Use an empty USB stick of at least 16 GB for the installation.
4. Keep the charger connected during the whole installation.
5. Keep the instructions: after each update you may need to apply the patches again.

Is a newer macOS what you actually need?

An old Mac is often not slow because of the software, but because of the hardware: a worn battery, a full or old drive, or cooling full of dust. A new battery or clean cooling sometimes does more for an older MacBook than a new macOS. Also read repair your MacBook or buy a new one.

What we do at Blue Apple in Amsterdam

We do not install the patcher for you, but we do look at the hardware. If your Mac no longer starts after an installation, or you first want to know whether your old MacBook is still worth it, we measure the battery, the storage and the temperature and tell you honestly what makes sense. More on our page about MacBook repair in Amsterdam.

Frequently asked questions

Is OpenCore Legacy Patcher legal?

The program itself is free and open source. You use it at your own risk, outside Apple's support.

Can I go back to my old macOS?

Yes, by erasing the Mac, reinstalling the old version and then restoring your backup.

Does it work on a Mac with an Apple chip?

No. Those Macs get their updates straight from Apple and do not need the program.