If your Mac has suddenly become slow, started freezing, feels hot or keeps showing the spinning beach ball, it does not automatically mean that it is worn out. Most slowdowns come down to a resource-hungry app, low free storage, too many items running in the background, browser overload or temporary work macOS is doing after an update.
This guide shows you how to find the cause before changing anything drastic. It applies to both Apple-silicon and Intel Macs, although the settings may be named slightly differently on older versions of macOS. If you have an Intel Mac, use the most recent macOS version that it supports; macOS 27 Golden Gate itself is for Apple-silicon Macs.
Start here: the five fixes most likely to work
Before reinstalling macOS, buying a new Mac or installing a “cleaner” app, work through these in order:
- Restart your Mac.
- Make some room on the startup disk if it is close to full.
- Use Activity Monitor to identify an app that is using excessive CPU or memory.
- Remove unnecessary login items and background activity.
- Install pending macOS, app and browser updates, then allow time for post-update background tasks to finish.
For a sudden slowdown, Activity Monitor is normally the fastest place to find a real answer. For a Mac that has always been slow, storage, memory and the age of the hardware matter more.
Match the symptom to the likely cause
| What you notice | Likely cause | Start with |
|---|---|---|
| Your Mac was fine, then suddenly becomes slow or noisy | A runaway app, browser tab or background process | Activity Monitor |
| You see the spinning beach ball when switching apps | Memory pressure or an app that has stopped responding | Activity Monitor’s Memory tab |
| Your Mac is slow after a macOS update | Spotlight, Photos, iCloud or other background tasks | Give it time, then check Activity Monitor |
| Startup and login take ages | Too many login items or background utilities | Login Items & Extensions |
| Only Chrome, Safari or one website is slow | Tabs, extensions, browser data or your connection | Test another browser and close extensions |
| The Mac is hot and the fans stay loud | Sustained CPU work, heat or a peripheral/software issue | Activity Monitor and a restart |
| Finder freezes, files will not open or the Mac will not start reliably | A disk, file-system or hardware issue | Back up, then use Disk Utility or Apple Diagnostics |
1. Restart your Mac, then see whether the problem returns
Restarting is not a cure-all, but it is the quickest safe first test. It closes apps and background processes that may have got stuck, clears temporary memory pressure and gives macOS a clean start.
Choose Apple menu > Restart. Save your work first and untick “Reopen windows when logging back in” if you want a genuinely clean restart.
If the Mac becomes slow again soon afterwards, note what you were doing when it happened. If it only returns when you open one app, reconnect a particular drive or visit a particular website, you have a much better lead than “the whole Mac is slow”.
You do not need to restart on an arbitrary weekly schedule. It is useful when your Mac is misbehaving, after certain updates or when it has been running a long time with lots of work open.
2. Use Activity Monitor to find what is actually slowing your Mac
Activity Monitor is the Mac equivalent of Windows Task Manager. It is built into macOS and is far more useful than guessing which app is to blame.
Open it from Applications > Utilities > Activity Monitor, then look at these tabs:
Check CPU first
Click CPU, then click the % CPU column heading to sort the list. An app that stays near the top and continues using a very high percentage while you are doing nothing is worth investigating.
Select the app and click the stop button in the toolbar. Try Quit first. Use Force Quit only if the app has stopped responding, as force-quitting can lose unsaved work. If you cannot get that far, see our guide to Force Quit on a Mac.
Do not force-quit random Apple processes just because their names are unfamiliar. Some will use noticeable CPU temporarily while macOS indexes files, syncs data or updates an app. The useful clue is sustained activity that lines up with the slowdown.
Then check Memory Pressure
Click Memory and look at the Memory Pressure graph at the bottom of the window:
- Green means memory is being managed normally.
- Yellow means macOS is under increasing memory pressure.
- Red means apps are asking for more memory than the Mac can provide efficiently.
Do not judge this simply by how much “free” memory is shown. macOS uses available memory to make apps responsive; the Memory Pressure graph and frequent swapping are much better indicators of a real problem.
Browsers, video-editing tools, large design files, virtual machines and a large number of Electron-based apps are common causes. Close the app or tabs you are not using, update the offending app and see whether the graph returns to green.
3. Make space on your startup disk — but do it safely
Very low storage can make a Mac feel slow because macOS needs working space for temporary files, memory swap, updates and caches.
Go to Apple menu > System Settings > General > Storage to see the categories taking up space. On older versions of macOS, the route may be Apple menu > About This Mac > Storage > Manage.
You can find out exactly which files are taking-up the most space by clicking on the “i” symbol in each category and delete the biggest ones that you don’t need by Ctrl-clicking on the ones you no longer need.
To get rid of video files you may no longer need, you can also use the Optimize Storage feature in macOS to delete movies you have already watched.
As a sensible rule of thumb, try to keep roughly 10–20% of the startup disk free where practical. It is not a magic threshold, but a 256GB Mac with only a few gigabytes free needs attention much more urgently than one with tens of gigabytes available.
Start with the low-risk items:
- Empty the Bin once you are sure you no longer need its contents.
- Review Downloads for old installers, disk images and duplicate files.
- Move large videos, archives and completed projects to reliable external storage or cloud storage.
- Use the Storage recommendations to review large files, old iPhone or iPad backups and downloaded TV content.
For a visual view of your disk, see our guide to finding large files and checking storage on a Mac. A tool such as DaisyDisk can also be helpful when the built-in Storage categories are not clear, but review a folder before deleting anything.
Do not manually remove files from the System or Library folders, or indiscriminately delete caches because a cleaning app tells you to. macOS already clears many temporary files safely when space is needed. Deleting the wrong support file can create a much harder problem than a full disk.
4. Remove unnecessary login items and background activity
An app does not need to be visible in the Dock to slow your Mac down. Cloud-storage clients, menu-bar tools, update checkers, VPNs, browser helpers and old utilities can all start automatically and keep running.
On current macOS versions, go to Apple menu > System Settings > General > Login Items & Extensions. Review both:
- Open at Login: apps that launch whenever you sign in.
- App Background Activity: apps that can continue doing work when their window is closed.
Remove or turn off items you recognise and do not need. Restart afterwards and see whether startup or general responsiveness improves. If you are troubleshooting a serious startup issue, remove items one at a time or make a note of them first so that you can add back anything essential.
Do not disable security software, a backup tool, a VPN required by work or a device driver unless you understand what it does. The goal is to remove needless background work, not to make useful software stop working.
For more help, check our guide on how to stop apps launching automatically on a Mac.
5. Treat browser problems as browser problems
If the rest of macOS feels responsive but web pages, video calls or one browser are slow, your Mac may not be the underlying problem.
First, close unused tabs and quit the browser completely. Then remove or disable extensions that you no longer use. Extensions can use memory, process page content and keep running on every site you visit.
Open the same page in another browser — Safari is a good control test on a Mac. If Safari is quick but Chrome, Firefox or another browser remains slow after a restart, focus on that browser’s extensions, profile and updates rather than trying to “speed up” macOS.
If every browser is slow only on websites or cloud services, test your Wi-Fi or broadband connection. A poor connection, VPN, DNS issue or slow service can look exactly like a slow Mac. Our roundup of the best browsers for Mac can help if you want to compare alternatives.
6. Give macOS time after an update, then update the rest
It is normal for a Mac to feel temporarily busy after a major macOS update or a large Photos/iCloud migration. macOS may re-index files for Spotlight, analyse photos, sync data and complete installation tasks in the background.
If this is the pattern, keep the Mac connected to power and Wi-Fi for a while, then check Activity Monitor rather than immediately trying advanced fixes. Performance should settle once the background work ends.
If it is still slow the following day:
- Restart the Mac.
- Install any follow-up macOS updates in System Settings > General > Software Update.
- Update the apps you use most, particularly your browser, cloud-storage client and creative or office tools.
- Check Activity Monitor again for one process that remains unusually busy.
Normal updates can resolve genuine performance and compatibility issues. If you are considering a brand-new major macOS release during an important deadline, back up first and check that critical apps, plug-ins and peripherals support it before upgrading. For a full walkthrough, see how to update a Mac.
7. Rule out your network, peripherals and external drives
Not every apparent slowdown starts inside your Mac.
If Finder hangs only when you connect a particular external drive, eject it safely and test the Mac without it. A failing drive, dock, hub or device utility can affect Finder, startup and app responsiveness. Reconnect one item at a time to isolate the culprit.
For web-based apps, video calls and cloud documents, compare a local task with an online task. If local apps are responsive but only online work is slow, test another network or temporarily disconnect a VPN if your organisation allows it.
Printers, scanners and old device software can also install background helpers. Check the relevant app or driver for an update before assuming you need to erase your Mac.
8. Take persistent heat and loud fans seriously
Fans are normal when your Mac is exporting video, compiling code, running a virtual machine or handling a demanding game. They are not normal if the Mac is hot and loud while sitting idle after a restart.
Start by checking Activity Monitor. Do not try to quit kernel_task if you see it using a high percentage of CPU; it is part of macOS and can appear more active when the Mac is managing temperature.
Instead:
- Use a MacBook on a hard, flat surface so its ventilation is not blocked.
- Disconnect non-essential hubs, drives and displays while you test.
- Quit the app that is genuinely using CPU.
- Shut the Mac down and let it cool if it has become unusually hot.
If it repeatedly overheats at idle, shuts down unexpectedly or has abnormal fan behaviour after a restart and software update, it is time to run Apple Diagnostics or arrange a hardware assessment.
9. Use Safe Mode and Disk Utility for the right problems
Test in Safe Mode
Safe Mode is useful when you suspect an incompatible login item, extension or third-party software. It is a diagnostic test, not a permanent way to make a Mac faster.
Follow Apple’s Safe Mode instructions for your type of Mac, test whether the issue still occurs, then restart normally. If the Mac is smooth in Safe Mode but slow normally, revisit login items, extensions and recently installed software.
Run First Aid when the symptoms point to storage errors
Use Disk Utility > First Aid if the Mac frequently freezes, reports file errors, cannot mount a drive or has startup problems. Back up first if you can. First Aid checks and attempts to repair the file system; it is not a general-purpose performance booster.
Apple explains how to repair a storage device with Disk Utility. If it repeatedly reports errors it cannot repair, back up immediately and seek help rather than continuing to use the drive normally.
10. Consider whether the limitation is hardware, especially on an older Intel Mac
An Apple-silicon Mac can still slow down because of a heavy app, too little unified memory or a background process. On an older Intel Mac, the hardware can also be the limiting factor — particularly a model with a mechanical hard drive or Fusion Drive.
Some older Intel Macs can be upgraded with more RAM or an SSD, but many cannot. Check your exact model before buying parts. An SSD upgrade can make a major difference to an eligible older Mac; adding RAM only helps where it is actually upgradeable and memory pressure is consistently high.
On Apple-silicon Macs, you cannot upgrade unified memory after purchase. If Memory Pressure is regularly yellow or red in your normal workload even after closing unnecessary apps, the practical answer may be to use less demanding software, reduce the number of concurrent apps or eventually move to a Mac with more memory.
If a particular app on an Apple-silicon Mac is always slow, use Activity Monitor’s Kind column to see whether it is running as an Intel app through Rosetta. Updating that app to a native version can help, but do not assume that one Intel app explains every slowdown.
11. Avoid these common “fixes” that often waste time
This is where many slow-Mac guides go wrong.
Do not install a cleaner app as your first response
A cleaner cannot fix an app that is consuming CPU, a memory bottleneck, poor Wi-Fi or failing hardware. It may remove caches that macOS will simply recreate, and it introduces another app with background access to your Mac. Use Activity Monitor and the built-in Storage settings first.
Do not force-quit every app at once
Closing everything in a panic can lose work and does not tell you what caused the slowdown. Identify the process that is consuming resources, then force-quit that one app normally if possible.
Do not reset NVRAM or the SMC for a generic performance problem
Those steps are for specific hardware, power, display or fan issues on relevant Macs. They do not solve low storage, browser overload, memory pressure or a runaway app. Apple-silicon Macs do not have a separate manual SMC reset in the way older Intel Macs do.
Do not assume a factory reset is the next step
Erasing a Mac or reinstalling macOS should be near the end of the process, after you have backed up and tested the simpler causes. A reinstall can help if system files or configuration are genuinely damaged, but it will not improve slow broadband, an overloaded website or inadequate hardware.
Do not assume every slowdown is malware
Most slow Macs are not infected. A trusted malware scan makes sense if you see unexpected adverts, unfamiliar browser extensions, a changed home page or search engine, apps you did not install, or suspicious background items. Otherwise, start with the much more common CPU, memory, storage and login-item checks above.
12. Reinstall macOS only after you have ruled out the obvious
If the Mac remains slow after a clean restart, plenty of free storage, app and macOS updates, a login-item review and a Safe Mode test, reinstalling macOS can be a sensible last software step.
Make a current Time Machine backup first. Apple says a standard reinstall does not normally remove your apps or personal data, but a backup protects you if the problem turns out to be a failing drive or the process does not go as expected. Follow Apple’s current guide to reinstalling macOS rather than using old key-combination advice for a different Mac type.
If a cleanly reinstalled Mac is still slow with only Apple apps open, the evidence points more strongly to hardware, memory limits or a peripheral issue. At that point, a repair assessment or replacement decision is more useful than another cleaning utility.
How to keep your Mac responsive
- Keep a meaningful amount of free storage on the startup disk.
- Keep macOS, browsers and frequently used apps up to date.
- Review Login Items & Extensions when you install or remove major software.
- Keep browser tabs and extensions under control.
- Restart when a problem appears rather than letting a stuck process run indefinitely.
- Back up regularly, especially before troubleshooting disk errors or major macOS upgrades.
FAQ
Why is my Mac so slow all of a sudden?
The most likely causes are a runaway app, too many browser tabs or extensions, a background task after an update, low free storage or a peripheral that is causing problems. Open Activity Monitor and sort by CPU, then check Memory Pressure to identify the actual bottleneck.
Why is my Mac slow after updating macOS?
Major macOS updates can trigger temporary indexing, photo analysis and cloud syncing. Leave the Mac on power and Wi-Fi for a while, then check Activity Monitor. If the slowdown remains the next day, restart and install any follow-up macOS and app updates.
Will deleting files make my Mac faster?
It can, but mainly when the startup disk is nearly full. Deleting or moving large, unneeded files creates room for macOS to use for temporary work and memory swap. It will not fix an app that is overusing CPU or a poor internet connection.
How do I know whether my Mac needs more RAM?
Use Activity Monitor’s Memory tab. Repeated yellow or red Memory Pressure during your normal work is a stronger signal than the amount of free RAM shown. Only some older Intel Macs can be upgraded; Apple-silicon Macs cannot have their unified memory upgraded later.
Should I use a Mac cleaner to speed up my Mac?
Not as a first step. macOS already manages many temporary files itself. Check storage, login items and Activity Monitor first; a cleaner will not fix a memory, CPU, network or hardware bottleneck.
When should I get my Mac repaired?
Back up and seek support if Disk Utility repeatedly reports unrepairable errors, the Mac overheats or shuts down at idle, it does not start reliably, or it remains slow after a clean reinstall with only Apple apps open. Those symptoms are more likely to indicate a hardware or storage problem than routine software clutter.