Mac Running Slow? 10 Speed Fixes That Actually Work (Apple Silicon & Intel)

A Mac that feels slower than it used to isn’t necessarily getting old — it’s usually doing something specific that’s eating resources, and once you identify it, the fix is often straightforward.

The challenge is knowing where to look. “My Mac is slow” is a symptom, not a diagnosis. Slowness during video editing is a completely different problem from slowness when you open Safari. A Mac that bogs down at startup is different from one that gradually degrades throughout the day.

This guide takes you through 10 targeted fixes — starting with the ones that solve the problem for most people in under two minutes, and working up to more thorough approaches for persistent issues. You won’t need any third-party software, and nothing here risks your data.

Related: Mac Maintenance: What to Do Monthly (And What to Never Do)

▶  Watch the video version of this guide on the CrazyErrors YouTube channel

First: Identify What Kind of Slow You’re Dealing With

Before trying any fix, spend 30 seconds narrowing down the symptom. Different kinds of slowness have different causes.

This sounds too simple to be worth mentioning, but it genuinely resolves a wide range of slowdowns — and most people skip it because they close the lid instead of shutting down.

When you close the lid, your Mac enters sleep mode. Apps stay open, processes stay running, and memory doesn’t get cleared. Over days or weeks of sleep cycles, temporary files accumulate, memory allocation becomes fragmented, and some background processes gradually consume more resources than they should. A full restart resets all of this.

1. Click the Apple menu → Restart.
2. Uncheck “Reopen windows when logging back in” — this prevents all your previous apps from re-launching automatically.
3. Click Restart and let it complete fully before opening anything.

Activity Monitor is macOS’s built-in task manager. It shows exactly which processes are consuming your CPU, memory, energy, and disk — and it often reveals the single app or background process responsible for most of your slowdown.

How to use it:

1. Open Spotlight (Command + Space), type Activity Monitor, and press Enter.
2. Click the CPU tab. Click the % CPU column header to sort highest to lowest.
3. Look for any process using more than 50–80% CPU when you’re not actively doing anything intensive.
4. Click the Memory tab. Check the Memory Pressure graph at the bottom.

What the Memory Pressure colours mean:

• Green — your Mac has healthy available RAM. Memory isn’t the issue.
• Yellow — memory is under moderate pressure. Consider closing apps you’re not using.
• Red — your Mac is regularly running out of RAM and is using the disk as overflow (called “swap”). This causes significant slowdowns and usually means you need to close apps or, long-term, consider a Mac with more RAM.

Login items are everything that launches automatically when you start your Mac. Each one adds to startup time and runs persistently in the background. On a Mac that has accumulated software over a year or two, this list often has far more entries than most users realise.

How to trim Login Items:

1. Go to Apple menu → System Settings → General → Login Items & Extensions.
2. Look through the list under “Open at Login.”
3. Select anything you don’t need running at startup and click the minus (–) button to remove it.

Common things safely removed from Login Items: cloud storage apps you rarely use, printer utilities, creative suite helpers (Adobe updaters, etc.), app assistants, and anything you don’t recognise from a recent installation.

Web browsers — particularly Chrome and Firefox — are among the most resource-intensive applications on a Mac. Each open tab runs its own process and consumes memory. Fifty tabs in Chrome can consume several gigabytes of RAM, leaving less available for everything else.

What to do:

• Close browser tabs you’re not actively reading. Use bookmarks or a read-later app like Pocket if you want to save them.
• Quit applications entirely when you’re not using them — don’t just minimise them. A dot under an app in the Dock means it’s still running. Right-click → Quit to close it fully.
• Check your browser’s built-in task manager: in Chrome, go to the three dots → More Tools → Task Manager. Sort by Memory Footprint to see which tabs are heaviest.

When your startup disk is nearly full, macOS performance degrades in multiple ways. The system needs free space to write swap files (overflow memory to disk), create temporary files during app operation, and handle background processes. A Mac with less than 10GB free will often feel sluggish even on modern hardware.

How to check and free storage:

1. Go to Apple menu → About This Mac → More Info → Storage Settings.
2. Review what’s using space. Click the arrow next to any category for details.
3. Empty the Trash, clear the Downloads folder, and remove large files or apps you no longer need.
4. Move large video files or project archives to an external drive if your internal storage is tight.

Spotlight is macOS’s search and indexing system. After a major software update or if you’ve moved a lot of files, Spotlight can enter an extended re-indexing process that runs in the background and consumes significant CPU. This is often mistaken for a general slowdown when it’s actually a temporary process.

How to check if Spotlight is indexing:

1. Look at the Spotlight icon in your menu bar — a dot or pulse animation beneath it indicates active indexing.
2. In Activity Monitor, look for a process called mdworker or mds_stores using high CPU. These are Spotlight’s indexing processes.

If Spotlight indexing is running, the best approach is simply to wait — it will finish on its own, usually within a few hours of normal use. If it appears to be stuck and has been running for more than 24 hours:

1. Go to System Settings → Siri & Spotlight.
2. Click Spotlight Privacy.
3. Add your startup disk (Macintosh HD) to the exclusion list using the plus (+) button.
4. Wait 30 seconds, then remove it from the list.
5. This forces Spotlight to rebuild its index fresh.

Software updates often include performance improvements, bug fixes for memory leaks, and compatibility corrections. A Mac running an outdated macOS version can experience slowdowns from issues that Apple has already patched in a newer release.

Update macOS:

1. Apple menu → System Settings → General → Software Update.
2. Install any available updates. Back up with Time Machine first if you haven’t recently.

Update your apps:

1. Open the App Store.
2. Click Updates in the sidebar.
3. Click Update All or update apps individually.

For apps installed outside the App Store (like Chrome, Zoom, or Office), check for updates within the app itself — usually under the app name menu or Help → Check for Updates.

NVRAM stores system settings like startup disk selection and screen resolution. The SMC (System Management Controller) manages hardware functions including power, fans, and thermal behaviour. When either of these becomes corrupted, it can cause persistent performance issues that normal troubleshooting doesn’t resolve.

Reset NVRAM (Intel MacBooks):

1. Shut down your Mac completely.
2. Turn it on and immediately press and hold Command + Option + P + R together.
3. Hold all four keys for about 20 seconds — the Mac may restart during this time. That’s normal.
4. Release the keys and let it boot normally.

Reset SMC (Intel MacBooks with T2 chip, 2018–2020):

1. Shut down your Mac.
2. Press and hold Left Shift + Left Control + Left Option on the keyboard.
3. While holding those three keys, press and hold the Power button as well.
4. Hold all four keys for 10 seconds, then release everything.
5. Wait a moment, then press Power to start normally.

If your Mac felt fast before a macOS update and started feeling slow immediately after, you’re not imagining it — and you’re not stuck with it. macOS does several intensive background tasks in the first 24–48 hours after a major update: re-indexing Spotlight, optimising photos, re-syncing iCloud, and recompiling app caches. This is temporary and usually resolves on its own.

What to do after a slow update:

1. Wait 48 hours. Plug the Mac in, leave it idle for a few hours overnight, and let the background processes finish. Most post-update slowdowns resolve entirely within 1–2 days.
2. Check Activity Monitor for processes like Photos Library, mds_stores, or cloudd using high CPU — these are the common background workers after an update. They will complete.
3. Restart once more after the first 48 hours. This often clears any remaining post-update processes.
4. If slowness persists beyond 3–4 days, check for a follow-up patch. Apple typically releases a .0.1 or .1 stability update within weeks of a major release that addresses widespread performance issues.

If you’ve worked through all nine fixes above and your Mac is still consistently slow, a macOS reinstall is the most thorough software solution available. Reinstalling macOS replaces all system files without deleting your personal data — your apps, documents, photos, and settings remain untouched.

For Apple Silicon Macs (M1, M2, M3, M4):

1. Shut down your Mac.
2. Press and hold the Power button until “Loading startup options” appears.
3. Click Options, then Continue.
4. Enter your password when prompted.
5. Select Reinstall macOS and follow the prompts.

For Intel MacBooks:

1. Shut down your Mac.
2. Turn it on and immediately hold Command + R.
3. Release when the Apple logo or spinning globe appears.
4. Select Reinstall macOS and follow the on-screen instructions.

Quick Diagnostic: Match Your Symptom to the Right Fix

Frequently Asked Questions

Final Thoughts

A slow Mac almost always has a specific cause — and the fixes above cover the full range of what that cause is likely to be. Work through them in order from Fix 1, and you’ll identify the issue within the first few steps in most cases.

The fixes most people skip because they seem too simple — restarting, trimming Login Items, freeing storage — are also the ones that resolve the problem most often. Start there before reaching for more advanced solutions.

If you’ve been through all ten fixes and your Mac is still noticeably slow, it’s worth checking with Apple Support. At that point, you’ve ruled out all the common software causes, and a hardware or deeper software diagnosis makes sense.

Drop your Mac model and macOS version in the comments if a specific step isn’t working as expected — it may help others working through the same situation.