MacBook Running Slow? Speed It Up (2026 Guide)

Pro Tip

Key Takeaways:

• • Low storage space causes ~40% of MacBook slowdowns—keep 15-20% free
• • Too many startup items drain resources before you even begin working
• • Chrome with many tabs can consume 4-8GB+ of RAM alone
• • An SSD upgrade can make a 10-year-old Mac feel nearly new
• • Sometimes age is the honest answer—7+ year old Macs struggle with modern software

Diagnosing the Cause

Before trying random fixes, identify what's actually slowing your Mac. If your Mac is completely unresponsive (not just slow), see our freezing guide instead. Open Activity Monitor (Applications → Utilities) and check:

• CPU tab: Is anything using 100%+ constantly?
• Memory tab: Is "Memory Pressure" in the red?
• Disk tab: Are read/write operations maxed out?

Also check your storage: Apple menu → About This Mac → Storage. If the bar is nearly full, that's likely your problem.

Software Fixes

Start with these free fixes before spending money:

Restart Your Mac

Sounds obvious, but many Mac users never fully restart. RAM fills with cached data, swap files accumulate. A fresh restart clears it all.

Update macOS

Apple regularly releases performance optimisations. Check System Settings → Software Update.

Reset SMC and PRAM/NVRAM

These resets clear hardware-related settings that can cause odd behaviour:

• Intel Macs (SMC): Shut down, hold Shift+Control+Option+Power for 10 seconds
• Intel Macs (NVRAM): Restart, hold Option+Command+P+R for 20 seconds
• Apple Silicon: Just restart—these resets happen automatically

Free Up Storage Space

macOS needs 15-20% free space to work efficiently. When storage is full, the system can't create swap files, cache properly, or update.

• Empty Trash: Right-click Trash icon, Empty
• Clear Downloads: Sort by size, delete what you don't need
• Remove old iOS backups: System Settings → General → Storage → iOS Files
• Clear system cache: Use free tools like OnyX (carefully)
• Uninstall unused apps: AppCleaner removes apps and their associated files

Manage Startup Items

Too many apps launching at login = slow boot and constant background resource drain.

Check: System Settings → General → Login Items. Remove anything you don't need starting automatically.

Hardware Upgrades

If software fixes don't help, hardware might be the bottleneck:

SSD Upgrade (If HDD)

If your Mac still has a spinning hard drive (common in pre-2012 MacBooks), an SSD upgrade is transformative. Boot time goes from 90 seconds to 15 seconds. Apps launch instantly.

Cost: £129-£179 for 500GB including installation and data migration.

RAM Upgrade (If Possible)

Pre-2012 MacBook Pros can have RAM upgraded. Going from 4GB to 8GB or 8GB to 16GB makes a noticeable difference for multitasking.

Cost: £49-£129 depending on amount.

When Age Is the Problem

Sometimes a Mac is simply too old for modern software. Signs that age is the real issue:

• Mac is 7+ years old
• Can't install current macOS version
• 4GB RAM with no upgrade option
• Running the latest compatible macOS still feels slow
• Modern web pages and apps overwhelm it

A 2015 MacBook Air with 4GB RAM and a full SSD will never feel fast running 2026 software, no matter what you do. For model-specific advice, see our MacBook Air guide or MacBook Pro guide.

Repair vs Replace Decision

Not sure whether to invest in fixing your Mac? See our repair vs replace decision guide for a complete framework.

Frequently Asked Questions

Does Safari run faster than Chrome?

Generally yes. Safari uses significantly less RAM and energy on Mac. If Chrome is your slowdown culprit, try Safari for a week. You might be surprised.

Should I use a Mac cleaning app?

Free tools like OnyX are useful for cache clearing. Avoid paid "Mac cleaners" that promise dramatic speedups—most are unnecessary or even harmful. macOS manages itself fairly well.

Will reinstalling macOS help?

Sometimes. A clean install removes accumulated cruft. But if the slowdown is hardware-related (full storage, old HDD, insufficient RAM), a fresh install won't fix it.