# How Keep86 works

> **Short answer:** Keep86 runs a hidden macOS 27 virtual machine on your Apple silicon Mac, with Rosetta turned on inside it. Your Intel-only apps are installed there, and Keep86 shows each app’s windows on your normal desktop. You open and use them like any other app, without a second desktop to manage.

Keep86 is in public beta. This page describes how it is built; results for individual apps appear in the compatibility database only after we have tested them.

One question is still open: Apple hasn’t said whether macOS 28 will continue to run Rosetta inside a macOS 27 virtual machine. Keep86 depends on the answer. We will test this on the first macOS 28 betas (expected in June 2027) and publish the result on this page.

## One-time setup

- Scan — Keep86 lists the Intel-only apps on your Mac and points out those that have a native version you can download instead.
- Download macOS 27 from Apple — Keep86 downloads the official macOS 27 restore image directly from Apple’s servers. We never host or redistribute macOS.
- Create the virtual Mac — Keep86 creates the virtual Mac and asks how much memory it may use while it runs.
- Complete macOS setup — You go through the standard macOS setup screens once and create a local user account. You don’t need an Apple Account.
- Keep your apps — Choose the apps you want to keep. Keep86 copies them into the virtual Mac and adds a launcher with each app’s own icon to your Mac.

## Everyday use

- Open apps as before — Click the app in the Dock, Launchpad or Finder. If the virtual Mac is asleep, it wakes up and the app opens.
- Windows on your desktop — The windows, menus and dialogs of each kept app appear next to your other apps — not inside a second desktop.
- Your documents — Kept apps open and save files through a shared folder on your Mac, so your documents stay where you can find them.
- Sleep when idle — When you close your kept apps, the virtual Mac goes to sleep after a while and returns its memory to the rest of your Mac.

## What your Mac needs

- **An Apple silicon Mac** (M1 or newer) with macOS 27 or later. Intel Macs don’t need Keep86, because they run Intel apps natively.
- **About 65 GB of free disk space during setup** and about 40 GB afterwards, plus space for the apps you keep.
- **16 GB of memory recommended** (8 GB is enough for light apps). The virtual Mac reserves the memory you assign to it until it goes to sleep.
- **An internet connection** for the one-time macOS download and for licence refreshes every week or two. Offline, Keep86 keeps working until the current licence token expires.

## Privacy

Everything runs on your Mac. Keep86 never sees your apps, your documents or what you do with them. The licence check sends only a licence ID, a device key, a hashed hardware ID, an optional device name and the app version.