What’s the Newest macOS I Can Reasonably Install on a 2012–2015 Retina MacBook Pro?

If the Mac has 16 GB of memory and you only browse the web, Sequoia may be acceptable, and it provides a newer platform with ongoing security support for longer than Monterey. I would still expect reduced performance compared with Monterey and would choose the newest version that works reliably rather than automatically selecting the newest possible one.

Before upgrading, check that the browser and apps you depend on still support the target macOS version. Also make a full backup first, since a patched installation is unofficial and troubleshooting it can be more involved than reverting to the currently supported system.

Unofficial patching is possible, but the experience can be a little fragile because these models use older GPU hardware. You may need post-install fixes, and future updates could occasionally require extra troubleshooting. It is worth checking the patcher’s current compatibility notes before committing.

Ventura is probably a more sensible performance target on older 2012 hardware. Modern websites are often the bigger problem than macOS itself, since browsers and web pages have become much more demanding. Sonoma or Sequoia might boot and work, but they may not feel like an upgrade in everyday use.

OpenCore Legacy Patcher can make Sequoia install on these Macs, but it involves workarounds for unsupported hardware and older graphics drivers. Sequoia may be usable for light browsing, especially with 16 GB of RAM, but it will generally feel slower and less polished than a supported installation.