How to speed up an old Mac without buying anything

You can often make an old Mac feel faster for free by finding the one or two apps doing most of the work, stopping things that open at login, keeping fewer browser tabs open, updating your apps and leaving some of the disk free. None of this makes the hardware newer. But an old Mac usually has less room to spare, so the same background clutter that a new machine shrugs off is what you feel on an old one.

Work through the steps in this order. Each one costs nothing, and the first two usually matter most.

1. Find the heavy apps

A slow Mac is almost always slow because something is using a lot of the processor, the memory or the disk. Guessing wastes time, so look first.

The built-in way is the Force Quit window. Press Option-Command-Escape (⌥⌘⎋) and it lists your open apps. It will not tell you what each one is using, but an app that has stopped responding has “(not responding)” after its name, and that one is worth dealing with straight away.

To see actual use, you need a list that shows it per app. Foreman is one: open it with Control-Shift-Escape (⌃⇧⎋), go to Processes, and click the CPU column to sort. Apps are grouped with their helper processes, so a browser shows up as one row with its tabs’ helpers added up under it instead of twenty rows with strange names. Click Memory to sort by that instead. The row at the top of the sort is where to start. How to see which app is using the most CPU on a Mac goes through it step by step.

What you do with a heavy app depends on whether you need it:

• If you do not need it, quit it. In Foreman, End Task asks it to quit the normal way, so it can offer to save your work.
• If you need it open but not right now, Efficiency Mode keeps it running while it is in the background, held to about a quarter of the processor time it would take. In front, it runs at full speed again. That suits things like a mail app or a chat app that you want open all day.
• If it has stopped responding, give it a minute, then force quit it.

2. Trim what opens at login

On an old Mac this is often the biggest single change. Every app that starts at login takes memory and some processor time from the first minute, whether you use it that day or not. Over the years most Macs collect a lot of these: updaters, sync tools, menu bar utilities that were installed once and forgotten.

In System Settings, open General > Login Items & Extensions (Login Items on macOS 14). The “Open at Login” list is the apps that launch when you log in, with plus and minus buttons: select one and click the minus button to stop it. The “Allow in the Background” list has a switch for each helper program that apps run without a window. Switch off the ones you do not recognise or do not use, but be careful: some belong to things you do want, such as a backup tool or a password manager. If you are not sure what an item is, search for its name before you turn it off. Turning one off can be reversed.

Foreman’s Startup Apps page puts all of this in one list, grouped by the app each item belongs to, with a status for each. It also flags “Program missing” items, which are leftovers from apps you deleted long ago and which can be removed. How to stop apps opening at login on a Mac covers every route.

3. Keep fewer tabs and windows open

Browsers are the heaviest everyday software on most Macs. Each tab is a separate piece of work, and tabs that are playing video, running a web app or refreshing a page cost the most, even if you are not looking at them.

Do not count tabs. Find out which ones cost something. Sort by CPU or Memory and open the browser’s row to see its helpers. If one is far above the rest, it is usually one page: a video, a meeting, a heavy web app, or a page that has gone wrong and is using the processor for nothing. Close that one. How to tell if one browser tab is slowing down your Mac shows how to match a helper to a tab.

Closing the windows you finished with also helps. On an old Mac with limited memory, every open document, window and page is something macOS has to keep somewhere.

4. Update your apps, and check macOS

Older versions of apps can be slower than current ones, and some have bugs that keep them busy in the background. Open the App Store, or each app’s own update menu, and install what is waiting. For macOS itself, System Settings > General > Software Update shows what your Mac can install.

Be realistic about the macOS part. A newer macOS is not always better for an old Mac. If your Mac is running smoothly on the version it has, there is no need to hurry, and a big update can leave the Mac busy with background work for a day or two afterwards. Why is my Mac slow after a macOS update explains why that happens and when it settles.

5. Free up disk space

A disk that is nearly full slows a Mac down, because macOS needs free room to work in. Open System Settings > General > Storage to see what is taking the space. It shows what is using the space by category, with recommendations such as Store in iCloud, Optimize Storage and Empty Trash Automatically, and some categories let you look through the largest files and delete what you no longer need. The biggest wins are usually your own files: old downloads, large videos, iOS backups, and apps you stopped using.

Deleting apps and files is your decision, and no tool should make it for you. Foreman does not clean files or look at disk space, so use System Settings for this step.

6. Restart now and then

A Mac that has been on for weeks collects processes that have grown, apps that leaked memory and background jobs that never finished. Restarting clears all of that. You do not need a schedule, but if your Mac feels slow and has not been restarted in a long time, restart before you try anything else. Foreman’s Performance page shows how long the Mac has been up, which is a quick way to see how long it has been.

What this cannot fix

Be honest about the limits. If your Mac has limited memory, and the Memory page shows high pressure even with only the apps you really use open, the hardware is the limit, and no amount of trimming will change that. The same goes for an old hard drive, or a processor that is simply slower than what today’s apps expect. The steps above remove the avoidable load. They cannot add capacity.

A good test is to restart, open only the apps you actually work in, and see how it feels. If it is still slow then, the slowness is in the hardware. If it is fine, then the cause was the clutter, and you now know what it was.

If you want the heavy-app part to be quick, Foreman is $12 once, works on up to 3 Macs, and is free for 24 hours, so you can find the cause of your Mac’s slowness within the trial. It needs macOS 14 Sonoma or later. If your Mac cannot run macOS 14, Foreman will not run on it, but the Force Quit window and the habits above (fewer login items, fewer tabs, free disk space, a restart now and then) still apply.