How to Speed Up a Slow iMac: Step-by-Step Cleanup Guide

Ever feel like your iMac is running through molasses just to load a website? The spinning beach ball of doom is Apple’s way of saying, “I’m tired.” Don’t panic — it doesn’t mean your Mac is done for. It just needs a tune-up.

Here’s a simple checklist to speed up a slow iMac and get back to smooth browsing.

1. Restart & Update

Restart your iMac and check for updates:

• Apple Menu > System Settings > General > Software Update

• Update Safari, Chrome, or Firefox

2. Clean Up the Browser

If things only crawl when you’re online, the browser is the likely culprit.

• Clear cache & history (“All Time” for best results)

• Disable or remove unnecessary extensions

• Keep tabs under 10 open at once

3. Free Up Space

macOS slows down when storage is too full.

• See where you are ( Apple menu > About This Mac > Storage)

• Empty Trash

• Delete large files from Downloads

• Uninstall unused apps

• Aim for 15–20% free space

4. Check Activity Monitor

Applications > Utilities > Activity Monitor shows what’s hogging power.

• Sort by CPU or Memory

• Quit any app eating up resources

5. Repair the Disk

A quick “First Aid” can patch up hidden issues.

• Applications > Utilities > Disk Utility

• Select your hard drive > First Aid > Run

6. Tidy Up Startup Apps

Too many apps launching at startup = slow mornings for your Mac.

• Apple Menu > System Settings > General > Login Items

• Remove apps you don’t need to auto-launch

7. Bonus: For Older iMacs

• Run Malwarebytes to check for adware.

• If your iMac still feels sluggish, upgrading the RAM or switching to an SSD can be a game-changer. Best part? You don’t have to guess — take it into the Apple Store and they’ll test it, give advice, and often help with upgrades for free.

Final Thoughts to Speed Up Slow iMac

A slow iMac doesn’t mean it’s time to replace it- it usually just needs a little tech self-care. With a little decluttering, you can speed things up and keep your Mac running smoothly.

Navigating the tech forest so you can focus on the view is what I do best. If you’d rather not wrestle with spinning wheels and hidden settings on your own, let’s tackle it together. Book a time with me here so we can talk about what you need!