By The KTech team · Published 29 October 2026
Macs have a reputation for just working, and for the most part that is deserved. But a MacBook, iMac or Mac mini that has been in daily use for a few years can start to feel sluggish, with the dreaded spinning wheel appearing more and more often.
This guide covers the causes we see most, the safe checks you can do yourself, and how to tell when it is time to get a repair or think about a replacement.
Common causes
- Full storage. A Mac with very little free space struggles with everything, from updates to opening apps. Photos, videos and old downloads are the usual culprits.
- Too many apps at login. Programmes that start automatically use memory and processing power before you have done anything.
- Too little memory for today's use. Many tabs, video calls and large documents can overwhelm older machines with 4GB or 8GB of RAM.
- An old spinning hard drive. Some older iMacs and MacBooks still have one, and they are much slower than the solid-state drives used today.
- A failed or interrupted macOS update. This can leave a Mac in a half-finished state.
- Browser extensions and adware. Unwanted extensions can slow the browser and cause pop-ups.
- Heat and dust. Fans clogged with dust force the Mac to slow itself to keep cool.
- An old battery. A swollen or worn battery can affect performance, and a swollen one is a safety matter.
Safe checks you can do yourself
Restart your Mac fully. Many of us leave Macs asleep for weeks, and a restart can clear a lot of slowness.
Check your storage. In System Settings, go to General, then Storage. See what is using space, and move large files such as photos and videos to an external drive or cloud storage. Do not delete things you do not recognise, particularly in system folders.
Open Activity Monitor, found in Applications and then Utilities. Look at the CPU and Memory tabs to see whether one app is using far more than its share. If a browser tab or a particular app is the problem, closing it may be enough.
Look at login items. In System Settings under General, choose Login Items and remove apps you do not need to launch at start-up.
Make sure macOS and your apps are up to date. Check that your Mac is still supported by Apple's current software; very old models eventually stop receiving updates.
In your browser, remove extensions you did not choose to install and see whether things improve.
Things to be careful about
There are plenty of 'Mac cleaner' apps and pop-ups promising to speed things up. Some are useful, but many are heavy-handed or misleading, and a few are the problem rather than the cure. If a website announces that your Mac is infected, close the tab and do not call any number it shows. Our page on virus and malware removal explains what is real and what is not.
Do not erase and reinstall your Mac without a backup. Time Machine is built in and straightforward. Use an external drive, keep it connected for the backup, and then store it safely.
When a repair makes sense
A repair is a good idea when the Mac is otherwise sound. For older models, a faster solid-state drive can change things dramatically where one can be fitted, and extra memory helps on machines where it can be upgraded. Be aware that on most recent Macs the memory and storage are built in and cannot be changed later.
A battery replacement or a clean of the fans and vents can cure heat and shutdown problems. A failed update or a damaged system can often be fixed without losing your files, provided you stop before making things worse.
It may be time to think about a replacement if the Mac is too old to run supported software, if the screen or logic board has failed, or if repair costs would be close to the value of the machine. We will give you an honest view, and we will not recommend a repair that is not worth doing.
Protect your data first
If your Mac is making odd noises, will not start, or you suspect a failing drive, stop using it and get advice. Continuing to use a failing drive can make it harder to recover your files. Our Mac repair service starts by looking at the data.
We repair Macs for customers all over the area, and we cover Mac and computer repair in Kingsbridge at our workshop, as well as the surrounding villages.
Habits that keep a Mac healthy
Most of what keeps a Mac quick is ordinary housekeeping. Restart it every week or so, keep a comfortable amount of storage free, and install macOS updates when they arrive rather than putting them off for months. Keep a Time Machine backup running, so a problem never turns into a disaster.
Be selective about what you install. Every app that wants to run in the background or add a menu bar icon uses a little of your Mac. Remove the ones you no longer use, and download software from the App Store or the developer's own site, not from a search ad.
Look after the hardware too. Use the Mac on a hard, flat surface so air can circulate, and keep liquids away. If the fan is loud all the time, or the case feels unusually hot, get it checked before it causes damage.