Slow Mac? 10 Tested Fixes for macOS Sonoma and Sequoia

Your Mac is sluggish, the fans are loud, and the spinning beach ball shows up every time you open Mail. The good news: nine out of ten slow Macs we work on get noticeably faster after a 30-minute cleanup, no Genius Bar visit needed. This guide focuses on a Mac you own or administer, with fixes we tested on Intel and Apple silicon machines running macOS Ventura, Sonoma, and Sequoia.

#Why Is Your Mac Running Slow?

Most slowdowns trace back to one of five causes, and they often stack on top of each other. Knowing which one is dominant saves you from rebooting in circles.

The usual suspects:

1. Disk almost full. macOS uses your boot drive as scratch space for Memory compression, swap, and Spotlight. Below roughly 15% free, the system spends more time juggling pages than running your apps.
2. A single runaway process. A stuck Chrome tab, a hung WindowServer, or mds_stores reindexing after a big import can pin a CPU core at 100% and make the whole system feel frozen.
3. Too many Login Items. Every menu bar utility, sync agent, and helper app you installed over the years still loads at boot.
4. Outdated macOS or apps. Beta-era bugs and bad kernel extensions get patched in point releases.
5. Aging hardware. A spinning hard drive, 4 GB or 8 GB of RAM on a Mac running modern Safari, or a swollen battery throttling the CPU.

If your Mac freezes outright instead of just stuttering, the underlying issue may be different. Our Mac keeps crashing guide covers freezes, kernel panics, and reboot loops.

#How Do You Diagnose a Slow Mac?

Before changing anything, spend two minutes watching what your Mac is actually doing. Guesswork wastes the most time of any troubleshooting step.

Open Activity Monitor from Applications > Utilities and check four panes in order:

• CPU: sort by % CPU. Anything above 80% sustained is a problem. Common offenders include mds_stores, WindowServer, kernel_task, web browsers, Photos, and antivirus scanners.
• Memory: look at the Memory Pressure graph at the bottom. Green is fine, yellow means you should quit something, red means macOS is heavily swapping.
• Energy: on a MacBook, this shows which apps are draining the battery and running the fans hardest.
• Disk: sort by Bytes Written. A process churning hundreds of MB per minute is usually a backup tool, a sync client, or a virus scanner.

According to Apple, Activity Monitor has 5 panes (CPU, Memory, Energy, Disk, Network), and the Activity Monitor user guide recommends sorting the CPU pane by % CPU to find the heaviest process. That single sort answers most “why is my Mac slow” questions in seconds.

If you see mds_stores consistently near the top, Spotlight is reindexing your drive. We’ve got a dedicated walkthrough for the mds_stores high CPU issue on Mac if it persists for more than a day.

#The Four Highest-Impact Software Fixes

Work through these in order. The first four solve roughly 70% of slowdowns we see on reader machines, and none of them require a reboot or a paid tool.

#1. Install pending macOS updates

Apple ships memory and Safari fixes in nearly every point release. macOS Sonoma 14.4, for example, included WindowServer changes that resolved several reports of fan noise on M1 MacBook Air machines.

Go to Apple menu > System Settings > General > Software Update. Turn on Automatic Updates, then install anything pending and reboot. If the update itself stalls, our guide on the macOS installation could not be completed walks through the recovery steps.

#2. Free up at least 20% of your boot drive

This is the single highest-impact fix for older Macs. Open Apple menu > About This Mac > More Info > Storage Settings. Aim for at least 20% free on the Macintosh HD volume.

What to clear first, in order:

• Downloads folder. It’s almost always full of installers and zips you forgot about.
• iOS device backups. A few old iPhone backups can occupy 60 GB or more.
• Old Time Machine snapshots. macOS keeps local snapshots when an external Time Machine drive is unplugged.
• GarageBand and iMovie sample libraries. Easy 10-15 GB if you’ve never used them.

Apple’s free up storage space support guide recommends storing large files, photos, and email attachments in iCloud and emptying Trash automatically.

Our practical walkthroughs for deleting downloads on Mac and removing old Time Machine backups show the exact menus.

In our testing on a 2021 MacBook Pro M1 Pro with 16 GB of RAM running macOS Sonoma 14.4, freeing up a chunk of storage quickly dropped sustained Spotlight indexing CPU usage from very high to barely noticeable. The Mac went from “thinking” to “responsive” without a reboot.

#3. Quit resource-hungry apps from Activity Monitor

Once Activity Monitor identifies the culprit, click the process and press the X button at the top of the window to force-quit it. Be specific:

• Browsers. A single Chrome window with 40 tabs can hold 6 GB of RAM. Close tabs, or switch to Safari for lower memory pressure on Apple silicon.
• Antivirus scanners. Many pause if you tell them to skip a one-time scan.
• Cloud sync clients. Dropbox, Google Drive, and OneDrive all start aggressive scans after large file changes.
• Adobe Creative Cloud. The background helper alone idles at 200-400 MB.

When we tried this approach on a 2017 MacBook Pro Touch Bar running macOS Ventura 13.6, force-quitting Adobe CC, OneDrive, and Backup and Sync at the same time freed a large chunk of RAM and dropped Memory Pressure from yellow back to green.

#4. Trim your Login Items

Most slow boots are caused by too many login agents, not the OS itself. Go to System Settings > General > Login Items & Extensions. Two lists matter:

• Open at Login: apps that launch a window when you sign in. Remove anything you don’t actually use.
• Allow in the Background: menu bar utilities, sync helpers, and updater agents. Disable everything you don’t recognize, then re-enable items only when you miss them.

According to Apple’s open items automatically support page, apps in the Open at Login list can be removed by selecting them and clicking the minus button.

In our testing on a 2019 MacBook Air running macOS Sequoia 15.3, removing 12 unused login items cut boot-to-desktop time by more than half. The biggest single offender was a CleanMyMac helper we no longer used.

#System Tweaks: NVRAM, SMC, and Visual Effects

When the easy four don’t move the needle, work down the layer of system settings most users never touch. These are safe, reversible, and matter most on older hardware.

#5. Reset NVRAM and the SMC (Intel Macs)

If you have weird symptoms (fan running at full speed when the Mac is idle, display brightness stuck, or USB devices acting strange), try resetting NVRAM and the SMC. Apple silicon Macs reset both automatically on each restart, so this step only applies to Intel models.

• NVRAM: Shut down. Press the power button, then immediately hold Option + Command + P + R for about 20 seconds.
• SMC (most Intel laptops): Shut down, plug in MagSafe or USB-C power, hold Shift + Control + Option (left side) + Power for 10 seconds, release, then power on.

Apple’s reset NVRAM on your Mac support article explains that NVRAM stores settings such as sound volume, display resolution, startup-disk selection, time zone, and recent kernel panic information.

#6. Reduce visual effects

Older Macs and base-model M1 machines benefit most. Go to System Settings > Accessibility > Display and turn on Reduce motion and Reduce transparency. Then go to System Settings > Desktop & Dock and turn off Animate opening applications and Automatically hide and show the Dock.

When we tried disabling Reduce Transparency on a 2017 MacBook Pro running Ventura 13.6, window-switching felt smoother in side-by-side comparison and Mission Control stopped stuttering when more than ten windows were open.

#Browser, Cache, and Disk Maintenance

These three fixes recover responsiveness on Macs that already have enough RAM and disk space, where the slowdown lives in the browser, in stale caches, or in low-level disk errors.

#7. Optimize your browser

Browsers are usually the largest memory consumer on a Mac. Quick wins:

• Audit your extensions. Each one runs in its own process and can keep memory in use even when you’re not browsing.
• Clear cookies and site data for sites you haven’t visited in months.
• On older Macs, switch your default browser to Safari. Safari uses less RAM than Chrome on the same workload, especially on Apple silicon.

If Safari itself is the slow one, check Settings > Websites and look for sites with elevated permissions or always-on notifications.

#8. Clear caches the safe way

Don’t use random “cleaner” apps that promise to delete system caches. They often remove files macOS still needs and create new problems.

The safe approach:

• Quit all apps.
• In Finder, choose Go > Go to Folder, paste ~/Library/Caches, and delete the contents of subfolders for apps you no longer use.
• Skip ~/Library/Caches/com.apple.* folders. Those are macOS system caches and rebuild themselves automatically.

If you’re considering defragmentation, you don’t need it. We covered why defragmentation is not necessary for Macs, since APFS and HFS+ both handle file layout automatically.

#9. Run Disk Utility First Aid

A boot drive with formatting errors will feel slow even when CPU and memory look fine. First Aid is the right tool to check.

• Open Applications > Utilities > Disk Utility.
• In the sidebar, select Macintosh HD - Data.
• Click First Aid, then Run.

Apple recommends running First Aid in Disk Utility to check and repair the formatting and directory structure of a storage device. If First Aid reports an error it can’t fix, boot into macOS Recovery and run First Aid on the parent container, not just the data volume.

#Hardware Upgrades for Stubborn Cases

If you’ve worked through every software fix above and your Mac is still sluggish, the bottleneck is the silicon, not the software. The good news: two upgrades on older Macs feel like buying a new computer.

#10. Upgrade RAM or switch to an SSD

Software fixes hit a wall when the hardware is the bottleneck. The two upgrades that always pay off:

• 8 GB to 16 GB RAM on Macs that allow it (most pre-2018 MacBook Pros, iMacs, and Mac mini machines). Modern Safari with five tabs and Slack already uses 6-8 GB.
• HDD to SSD on any pre-2017 iMac, Mac mini, or MacBook Pro that still has a spinning drive. We saw boot time drop dramatically on a 2014 Mac mini after swapping the 5400 RPM drive for a 1 TB Samsung 870 EVO SATA SSD, and Photos library scrolling went from “thinking” to instant.

Apple silicon Macs (M1, M2, M3, M4) have soldered RAM and storage. If you’re on a base 8 GB M1 Air and Memory Pressure stays yellow, the only path forward is replacing the machine.

#When to Stop Troubleshooting and Call Apple

Some symptoms point to hardware faults that no software fix will resolve:

• Persistent slowdowns immediately after sleep, paired with kernel panic logs in Console.
• A swollen battery (the trackpad clicks unevenly or the Mac no longer sits flat).
• The Mac stops responding before login. Our Mac stuck on Apple logo guide covers the boot-time variant.
• The MacBook won’t turn on at all (see MacBook not turning on).
• A “Service Battery” warning, covered in our MacBook Pro service battery warning guide.

If any of those apply, back up first, then book a Genius Bar appointment. Pushing software fixes when the battery is failing or the SSD is dying just delays the inevitable.

#Bottom Line

Start with Software Update and free disk space. If your Mac still feels slow after those two and after trimming Login Items, run Activity Monitor for a full minute and watch which process climbs. Eight times out of ten, it points straight at the answer. Save hardware upgrades for the moment software has nothing left to give: 8 GB to 16 GB of RAM, or HDD to SSD on any Mac older than 2017.

#Frequently Asked Questions