A Guide to Cleaning and Speeding up Your Slow Mac

For macOS Tahoe

Intro

If you’re a Mac Voiceover user, there’s one thing you absolutely hate hearing: that an app is “not responding.” This may happen occasionally and only last for a few seconds, causing only minor annoyance, or it can happen frequently and significantly disrupt your workflow.

If it happens frequently or for more than a few seconds at a time when performing basic tasks, there is likely an underlying problem with your Mac, either software or hardware related. In this guide, I will give an overview of some of the most common causes and solutions, but keep in mind that unresponsive apps, or generally slow performance, are nonspecific symptoms, so there might be other explanations for the issues you’re experiencing.

A basic overview of your Mac’s hardware components

In this guide, I will refer to several key hardware components that, while not necessary to know a great deal about in order to use a Mac, may be helpful to have a basic understanding of in order to enhance your knowledge of how problems can occur and how they can be addressed.

The processor or central processing unit (CPU) is the chip that provides most of a device’s computational power. Therefore, the more apps and processes that are running at once and utilizing the CPU, the slower the device will perform. In practice, however, it is unlikely that everyday computing tasks like word processing, email, and web browsing, or even more intermediate tasks like photo editing and complex video rendering, would meaningfully tax the CPU of a modern Mac.

Storage, as the name implies, refers to the capacity of media, such as solid-state drives (SSDs) on modern Macs, to store data. If your Mac is running slower than expected, one of the most common causes is that the SSD is full or failing.

Random access memory (RAM) refers to a device’s capacity to multitask. Therefore, in a nutshell, the more RAM your Mac has, the more apps it can run at once.

General information about your Mac’s CPU, storage, RAM, and other components can be viewed by choosing Apple > About this Mac. More comprehensive information about these and other hardware, networking, and software components and capabilities can be found in System Information (located in the Utilities folder).

What does “not responding” mean?

The announcement that an app is “not responding” either means that there is a VoiceOver-specific issue that prevents it from interacting with the app’s interface, or, less commonly, that the app is utilizing a significant amount of system resources, preventing any user interaction with it. Typically, in the latter case, apps become temporarily unresponsive when performing particularly resource-intensive tasks, and should start responding when the task is complete.

In the former case, sighted users should be able to interact with the interface with a mouse or keyboard, as the issue is with the accessibility infrastructure rather than the app itself, whereas in the latter, the app is unusable for sighted users, and a visual indicator officially known as the spinning wait cursor, and colloquially known as the “spinning beachball of death” or “pinwheel of death” is displayed.

If VoiceOver announces that an app is not responding in the course of general, everyday use, the issue is likely accessibility-related. While such issues are usually the result of bugs in the app or macOS that developers must correct, they can often be temporarily resolved by Command-Tabbing away from the app, waiting for VoiceOver to announce that it is responding or “ready,” then Command-Tabbing back to it. If that doesn’t work, Command-Tab away from the app and turn VoiceOver off, wait a few seconds, then turn it on again.

Finally, if all else fails, force quit the app by Command-Tabbing to it and pressing Command-Shift-Option-Escape. Alternatively, you can choose Apple > Force quit (or press Command-Option-Escape), select the problem app in the resulting table, and click Force quit (or press Return). Command-Option-Escape is the closest thing to Control-Alt-Delete on Windows.

In the unlikely event that your Mac becomes completely unresponsive, perform a force shutdown by pressing and holding the Power button for about ten seconds, and then press it again to turn the Mac back on. Note that doing this will cause you to lose any unsaved work, so do this only as a last resort. If this problem occurs, there is likely a deeper problem with your Mac, which you may be able to resolve with the troubleshooting steps in the following sections of this guide.

When performing such tasks, whether manually or with the help of third-party maintenance utilities, it is important to update your software so you have the latest patches, and to back up your data so you have it in the unlikely event that something goes wrong. For more information on backing up the data on your Mac, check out this guide to using Time Machine, the Mac’s built-in backup utility.

Third-party maintenance utilities

Third-party maintenance utilities can improve the performance and responsiveness of your Mac by offering to bulk-delete unnecessary files, performing various maintenance tasks that macOS would typically complete in the background, and allowing you to configure system settings and parameters that may not be visible or easy to locate manually. While there are many apps that perform these functions, the one that I recommend in most cases is Onyx, which is free and accessible.

If you’re looking specifically for an app that will remove leftover files from previously installed apps, I would recommend AppCleaner. This free and accessible app displays a list of installed apps and allows you to delete them along with their associated support files, and can also be configured to trigger any time you move an app to the trash.

One important thing to note about Mac maintenance is that as you browse the web, you may encounter ads for apps that claim to speed up your Mac, free large amounts of storage space, remove malware, and generally address other nonspecific symptoms. However, if your Mac is running as you’d expect, some app being pushed in a web ad is not going to magically make it faster, and could potentially pose a security risk, as web ads are a common way for malicious actors to trick users into installing malware. That is why in general, I only recommend users install third-party maintenance utilities in order to address specific issues.

Manual tasks

If you decide to go the manual route, the following tasks can help improve the performance and responsiveness of your Mac, address issues, and help you isolate and identify the causes of slower than expected performance:

Check system resource usage

If specific apps are frequently becoming unresponsive or slowing down your Mac, you can use Activity Monitor to check how much of the CPU and RAM they’re using, as well as their impact on energy usage and disk and network activity. To do this, open Activity Monitor (located in the Utilities folder) and select what you want to view in the “Categories” radio group in the toolbar, such as CPU or memory. Review the table to the right of the toolbar to see which processes are most resource-intensive, and quit processes to make more system resources available by selecting them and choosing View > Quit process (or pressing Command-Option-Q). Note, however, that quitting a process associated with an open app may cause you to lose unsaved work or produce other unexpected results, so only quit processes if you know what they are and know you don’t need them running.

If you find that a particular app is using a disproportionate amount of system resources, try reinstalling it or contacting the developer with your findings. If you decide to contact the developer, it may be helpful to track the app’s resource usage over time, which could help identify patterns in the app’s behavior that are causing it to run inefficiently.

Declutter your desktop

While it is convenient to place your most used files on the desktop, the desktop process is constantly running. If there is an excess of files, it’s possible that the amount of RAM needed to display all of them in the window is subtracting from what would be available to complete user tasks. Therefore, if you have a lot of files on the desktop, it is a good idea to organize them into a couple of folders.

Review login items

Note: For an audio demonstration of this feature, check out the AppleVis Podcast episode: “How to Manage Login Items on macOS.

If you find that your Mac is slow to log in, you may have apps configured to open automatically, which can slow the login process. You can view your login items in System Settings > General > Login items & Extensions. Review the apps listed under the “Open at login” heading, and delete anything you don’t need to use immediately after you log into your Mac.

In addition, some apps include background processes that run even if the app isn’t open in order to automatically complete certain tasks or respond to changing conditions, such as checking for and installing updates. However, if you find that an app’s background processes are utilizing a disproportionate amount of system resources, you may want to revoke that app’s permission to run background processes by toggling it off under the “App Background Activity” heading. Note that disabling an app’s background processes may cause the app to not work as expected, so you may wish to perform additional research before doing so to determine those processes’ functions.

Reclaim and optimize available storage space

View storage information and space-saving recommendations

To help you make the best use of your Mac’s internal storage, macOS includes tools to locate and delete unnecessary files, prevent such data from accumulating over time, and store files remotely in order to save space locally. These tools can be found in System Settings > General > Storage. A breakdown of what types of data are taking the most space on your Mac is displayed, and macOS will give recommendations to make optimal use of this space, such as only storing recent iCloud Drive data locally, removing downloaded content from the TV app once it’s been watched, reviewing and removing space-intensive apps and resources, reviewing large files and folders where files commonly accumulate, and automatically removing items from the trash after thirty days.

If you opt to store files in iCloud, the entire contents of iCloud Drive will be displayed when you open the folder, but only recent files are stored locally; files are downloaded as you open them. For information about iCloud, check out the guide: “iCloud Explained”.

Manually locate large files

In addition to viewing large files in the storage settings discussed in the previous section, you can manually search for large files using Spotlight. If you have large files that you no longer need, you should delete them to save space. To do this:

1. Press Command-Option-Space to open the full search window, and click the “Hide search criteria” toggle button to reveal the advanced search options.
2. Choose “Other” from the criteria popup menu, select “file size” in the resulting table, and click OK; note that you can quickly jump to “file size” in the table by pressing the letter F.
3. Specify your search criteria. For example, you could search for files larger than 1GB.

The search results should show all the files matching the criteria you defined. Delete any files you don’t need, empty the trash, and restart the Mac.

Disable Apple Intelligence

If you don’t use Apple Intelligence features like Writing Tools, notification summaries, or Image Playground, you may be able to reclaim several gigabytes of space by disabling Apple Intelligence, which deletes the assets required for it to function. You can check how much space these assets are taking by going to System Settings > General > Storage, and clicking the “Show detail” button to the right of “macOS;” the precise amount of space taken depends on the specific features used and the data gradually accumulated through training. To disable Apple Intelligence, toggle it off in System Settings > Apple Intelligence & Siri.

Clear browser data

Over time, data from your web browser, such as history, caches, and cookies, can accumulate, occupying valuable storage space and potentially degrading performance. Therefore, if your web browser is not performing as expected, you may want to clear this data.

To clear history and associated website data in Safari, choose Safari > Clear history. To clear cookies and other data the website stored on your Mac while keeping history intact, choose Safari > Settings (or press Command-Comma), click the privacy button in the toolbar, and click Manage website data. The resulting dialog shows a table of websites that are currently storing data; select the individual websites you want to remove data for and click Remove, or click Remove all to remove all website data from the browser. Note that clearing cookies will sign you out of any websites you were previously signed into and which remember your computer when you visit them.

Clear caches and logs

Like browser data, caches and log files from macOS and your installed apps can accumulate, which have the potential to become corrupted and degrade performance. To clear this data:

1. In Finder, choose Go > Go to folder (or press Command-Shift-G) and type or paste “~/library” without the quotes.
2. In the folder that opens, open the caches folder, select all the files in it by choosing Edit > select all (or pressing Command-A), and move them to the trash.
3. Return to the Library folder and open the logs folder. Repeat the process: select and delete everything in that folder.
4. Choose Go > Go to folder (or press Command-Shift-G) and type or paste “/library” without the quotes. Repeat the process for the caches and logs folders in this location.

Note: In the Library folder at the root of your startup disk, you’ll be prompted to authenticate to delete files, as these are system rather than user files. Also, you may get an error that Finder cannot delete certain files in the Caches and Logs folders. It is generally okay to ignore this message and leave such files alone.

While you’re in the library folders, you can look for leftover files from apps you may have uninstalled. While apps place files in various locations inside the Library folders, many of them can be found in the “Application Support,” “Launch Agents,” “Launch Daemons,” “Preferences,” and “Saved Application State” folders.

Caution: The library folders contain essential files needed for apps and the operating system to function. Therefore, only delete files if you know what they are and know you don’t need them. When you’re done, restart the Mac and empty the trash.

Start up in safe mode

Note: This feature is only accessible with VoiceOver on Macs with Apple Silicon.

Safe mode is a feature of macOS that disables login items, third-party drivers, and legacy system extensions at startup, useful if an incompatible item in one of these groups is causing a problem with your Mac. In addition, system caches are cleared, and a light check of your startup disk is performed when starting up in safe mode, which can identify possible issues that could be causing slower-than-expected performance.

To start up in safe mode, start up the Mac while holding down the Power button, and interact with your startup disk (usually called Macintosh HD) in the grid that appears. Focus on the Continue button and route the mouse pointer to it by pressing VO-Command-F5, hold down the Shift key, and click the mouse. Maintenance tasks are completed once the Mac has finished starting; restart your Mac to exit this mode.

If you’re trying to isolate a particular issue, attempt to reproduce it when in safe mode, and again once you leave this mode. If the issue no longer occurs, it was likely resolved by the maintenance tasks that macOS performed. If it doesn’t occur when in safe mode but returns once you leave this mode, you may want to remove login items for third-party apps, update, remove, or reinstall any third-party drivers or legacy system extensions, or contact their developers for assistance. For more information, check out the Apple Support article: “start up your Mac in safe mode”, or for an audio demonstration, the AppleVis Podcast episode: “How and When to Start Your Mac in Safe Mode”.

Verify your disk

If your Mac is persistently unresponsive or apps frequently quit unexpectedly or “crash”, there may be a problem with your internal disk. If it is a problem with the integrity of the file system, it can usually be repaired with Disk Utility or in some cases, by reinstalling macOS. If you believe your disk is physically failing, however, you should back up your data and take your Mac to a professional for service. To assess the health of your disk:

1. Start up in macOS Recovery:
   • On a Mac with Apple Silicon, start up the Mac while holding down the Power button, interact with the “Options” group in the grid that appears, and click Continue.
   • On an Intel-based Mac, restart it while holding down Command-R; note that you’ll need either a built-in or USB keyboard for this to work.
2. Select your user account in the grid, click Next, and enter your password.
3. Click “Disk Utility” in the macOS Utilities window.
4. In Disk Utility, choose View > Show all devices (or press Command-2), select the item at the top of the table, and choose “Run first aid” from the context menu (accessed by pressing VO-Shift-M).
5. When the first aid process completes, repeat the process for the containers and volumes below the physical storage device. For some volumes, the Mac may appear to become unresponsive while they’re being verified; this is normal and should resolve when the first aid process is complete.

If Disk Utility reports problems with any of these items that it cannot repair, you should erase and reinstall macOS. To do this:

1. Start up and open Disk Utility in macOS Recovery as described earlier.
2. Choose View > Show all devices (or press Command-2) and select the item at the top of the table.
3. Choose Edit > Erase, (or press Command-Shift-E), enter a name for the disk, choose “APFS” from the “format” popup menu, and click Erase. Note that this process will erase all data on the disk.
4. When the erase process completes, quit Disk Utility, click “Reinstall macOS” in the macOS Utilities window, and follow the onscreen instructions to install it on your newly reformatted disk.

If the installation is successful, the Mac should restart into the macOS Setup Assistant, as if it were new from the factory. If the process fails or you continue to have problems, however, your disk may be physically failing; you should take your Mac into a professional for service.

Conclusion

This guide contains a number of possible solutions I am aware of to clean and speed up your Mac. More help is available in your Mac’s user guide, Apple Support, and the AppleVis forum, and if you have any questions or believe any of the information in this guide is inaccurate, sound off in the comments.