MacTidy

Guide

You upgraded to macOS 27. Now what?

A big upgrade moves your settings around, leaves a lot of disk space tied up, and quietly hands new permissions to apps you had forgotten about. Here is what to check, in the order that matters.

You can do all of this by hand. Nothing below needs an app. MacTidy is a faster way through the same list, and it shows you every change before it makes one.

  1. Get the installer off your drive

    The upgrade leaves a large installer in your Applications folder, and older macOS versions keep snapshots of the previous system for a while. Together that can be a serious amount of space on a smaller drive.

    Check /Applications for anything named "Install macOS". Drag it to the Trash and empty it. MacTidy lists both the installer and the space that old system files are holding, with the size beside each one.

  2. Re-check disk encryption

    FileVault should survive an upgrade, but it is the single setting most worth confirming. Without it, anyone who takes the Mac can read every file by pulling the drive out.

    System Settings, Privacy & Security, FileVault. MacTidy checks it on every scan and links straight to that pane.

  3. Look at what can start itself

    Upgrades and app updates are the two moments when login items and background services reappear. Some belong to apps you removed months ago.

    System Settings, General, Login Items & Extensions. Turn off anything you do not recognise. Nothing here is required for macOS to boot.

  4. Re-read the permission lists

    Screen recording, microphone, camera, accessibility and full disk access are the five worth reading line by line. An app that had a good reason two years ago may not still need it.

    System Settings, Privacy & Security. Take the entries one at a time. Revoking is reversible: the app will ask again if it genuinely needs it.

  5. Check the network settings that get switched on and left on

    Remote Login, file sharing, screen sharing and remote management are usually enabled once for a reason and then forgotten for years. Each one is a way into the machine.

    System Settings, General, Sharing. If you cannot remember switching it on, you probably do not need it.

  6. Turn down the reporting

    Analytics sharing, Siri recordings and personalised ads are separate switches in separate places. An upgrade is a reasonable moment to review them.

    Analytics sits under Privacy & Security, Analytics & Improvements. Personalised ads is its own entry. MacTidy can switch the ads setting off for you and opens the right page for the rest.

  7. Update everything else

    A new macOS often ships alongside updates for the apps that hook deepest into it: security tools, backup software, drivers, VPN clients. Those are the ones that break.

The faster way

Or read the whole list at once

MacTidy checks all of the above in one pass and shows you a single screen: what is on, what is off, and what each one would cost you to change. It makes the changes macOS allows an app to make, and walks you through the ones macOS keeps for you.

It never changes a setting because it sounded safer. Anything with a real cost stays off until you have read what it does.

Try free for 15 days How the levels work
The Security Level screen listing each protection, whether it is on, and what changing it costs.
One screen for every setting in the checklist above.

Common questions

Will cleaning up after an upgrade break anything?

Removing the installer and old caches is safe. Caches rebuild themselves. The risk in any cleaning tool is a tool that decides for you, which is why MacTidy shows the list first and deletes nothing until you press the button.

Do I need to do this after every update?

No. Small updates change very little. It is worth a pass after a major version, which is roughly once a year.

My Mac feels slower since upgrading.

Give it a day or two first. A new macOS re-indexes Spotlight and rebuilds caches in the background, and that is genuinely heavy while it runs. If it is still slow after that, look at what starts at login and what is holding memory.