macOS Sequoia Running Slow? How to Fix Freezing & Lag

The macOS Sequoia update brings exciting new features, but for some users, it has also introduced frustrating performance issues like system freezes, mouse lag, and the dreaded spinning beachball cursor. These slowdowns can make your Mac feel unresponsive and hinder your workflow.

If your Mac has become sluggish after the update, you’re not alone. The good news is that these problems are often solvable with some targeted troubleshooting. This guide will walk you through the most effective steps to diagnose and fix performance issues in macOS Sequoia.

Quick Fixes to Try First

Start with these simple solutions—they often resolve common post-update glitches.

1. Restart Your Mac

A simple restart can clear temporary system caches and resolve many minor software conflicts that cause lag.

Click the Apple menu in the top-left corner and select Restart.

2. Update macOS

Apple frequently releases patches to fix bugs found in major updates. The version that follows a major release (like macOS 14.1 or 14.2) often contains critical performance fixes.

Go to System Settings > General > Software Update and install any available updates.

3. Check Activity Monitor for Resource Hogs

A single misbehaving app could be consuming all your CPU or memory.

Open Activity Monitor (you can find it using Spotlight search).
Click the % CPU column to sort by CPU usage.
Look for any process using an unusually high percentage. If you find one, select it and click the Stop (X) button to quit it.

Intermediate Troubleshooting Steps

If the quick fixes don’t work, the issue might be with incompatible software or system extensions.

4. Boot in Safe Mode

Safe Mode runs a check of your startup disk and loads only essential macOS components. This is a great way to see if the problem is caused by third-party software.

For Apple Silicon Macs: Shut down your Mac. Press and hold the power button until you see the startup options. Select your startup disk, then press and hold the Shift key and click “Continue in Safe Mode.”
For Intel Macs: Restart your Mac and immediately press and hold the Shift key until you see the login window.

If your Mac runs smoothly in Safe Mode, the issue is likely a login item or third-party application.

5. Manage Login Items and Third-Party Utilities

Software that runs in the background is a common culprit for slowdowns.

Go to System Settings > General > Login Items.
Review the list under “Open at Login” and remove any non-essential applications by selecting them and clicking the minus (– ) button.
Uninstall non-essential utilities like system cleaners, optimizers, or older VPN clients, as these can deeply conflict with macOS processes.

Advanced Solutions for Stubborn Problems

For persistent lag that won’t go away, these more comprehensive steps can help.

6. Use a Terminal Command to Fix Input Lag

Some users have reported that a specific autofill feature in Sequoia causes significant input lag. You can disable it with a Terminal command.

Open Terminal (found in Applications/Utilities).

Copy and paste the following command, then press Return:

defaults write -g NSAutoFillHeuristicControllerEnabled -bool false

Restart your Mac for the change to take effect.

7. Reinstall macOS

This is a nuclear option, but it often resolves deep-seated software corruption from a faulty update. This process does not erase your personal files or data.

Restart your Mac in Recovery Mode.
- Apple Silicon: Shut down, then press and hold the power button until you see startup options. Go to Options > Continue.
- Intel Macs: Restart and hold Command + R until you see the Apple logo.
From the Utilities window, select Reinstall macOS and follow the on-screen instructions.

Frequently Asked Questions (FAQ)

Q: Why is my Mac so slow after updating to macOS Sequoia?
A: The most common causes are incompatible third-party software (especially cleaners and VPNs), system extensions, or minor corruption during the update process itself.

Q: Will reinstalling macOS delete my files?
A: No. The “Reinstall macOS” option from Recovery Mode is designed to install a fresh copy of the operating system over the existing one, preserving all your user data, applications, and settings.

Q: Should I downgrade to an older macOS?
A: Downgrading is a complex process that requires a full backup and erase of your Mac. It’s generally recommended to try all troubleshooting steps first, as the next point update for Sequoia will likely fix the issues.

Final Recommendation

Start with a restart and software update. If the problem persists, boot into Safe Mode to test for third-party software conflicts. The Terminal command for input lag has proven effective for many users. The macOS reinstallation is your most powerful software-based solution before considering a hardware check.

By following this structured approach, you can systematically eliminate the causes of slowdowns and restore your Mac’s performance.