Keep Your Mac Running Smoothly with Onyx

Mac maintenance is far from glamorous, but if you take good care of your Mac, it will take good care of you. Onyx makes maintaining your Mac easier. Onyx is a free software package that collects a variety maintenance tools, scripts, and Terminal commands into one easy-to-navigate GUI. For first time users, there’s a lot to explore, so use this guide to get your bearings.

Download and Install Onyx

1. Download Onyx from the developer’s website. There’s a specific version of Onyx for every version of macOS, so make sure you download the correct one.

mac maintenance download onyx

2. Install Onyx from the downloaded disk image.

Starting Onyx

1. Open Onyx from the Applications folder.

mac maintenance onyx applications folder

2. The first time you run Onyx, you’ll need to approve it through macOS’s gatekeeper dialog. Click “Open” to run the program.

3. You’ll also need to enter your administrator username and password. Because Onyx can fiddle with deep system functions, it needs admin access to run. It won’t make any changes until you actually do something, so you can click “OK” without fear.

mac maintenance onyx password

4. You’ll also need to agree to Onyx’s terms of use. After you read them, untick “Display at launch” to avoid seeing the agreement at each launch. Click “Agree” when you’re done.

mac maintenance onyx agreement

5. Here’s our finally preparatory step: Onyx likes to verify the integrity of your system disk up front. This way, it can run maintenance tasks more quickly. You don’t have to do this, but it only takes a few moments, and it’s worth the check.

mac maintenance disk verification

6. Once the disk scan has been completed successfully, click “OK.”

mac maintenance disk verification ok

7. Onyx’s default screen actually includes no options. To access the functionality of the app, you’ll need to go through the various tabs, which we’ll walk through one by one.

mac maintenance onyx menu bar


If we move from left to right, the first tab we’ll encounter is labelled “Maintenance.” This tab contains some functions that might be familiar with Disk Utility users.

mac maintenance onyx menu bar maintenance

1. Under the first tab, “Structure of the Disk,” you’ll see the result of the disk verification process that you ran when you started Onyx. You can also re-run the verification by clicking “Check” in the bottom right.

mac maintenance onyx disk structure

2. The “Permissions” tab allows you to repair your home directory’s permissions. This is a common troubleshooting step for macOS errors, though it’s typically not as effective as legend would have it.

mac maintenance onyx permissions

3. The “Scripts” tab is where you can see log files for macOS’s built-in maintenance functions, which run weekly, daily and monthly.

mac maintenance onyx scripts

4. Finally, “Rebuilding” will help you rebuild a variety of system caches. These are the kinds of things you don’t want to tweak unless you’re sure you need to.

mac maintenance onyx rebuilding



mac maintenance onyx menu bar cleaning

Like the “Maintenance” tab, “Cleaning” exposes a variety of system functions for easy access. For the most part the “Cleaning” tab is about removing caches, so you’ll see a variety of caches that you can erase. If you’re having problems with an underlying system on your Mac, cleaning caches will often help you resolve the problem or locate its source. It can also help free up disk space on storage-restricted Macs. Most of these caches can be cleared without issue, since the system will just rebuild them as needed.

1. The “System” tab holds check boxes for a variety of system caches, include the boot cache and kernel cache.

mac maintenance onyx cleaning system

2. The “User” tab allows you to clear user-specific caches, like the Applications cache, the QuickLook cache, and the Dock cache.

mac maintenance onyx cleaning user

3. “Internet” holds caches for browsers, DNS, cookies, downloads, and more. You can some of these through your browser as well.

mac maintenance onyx cleaning internet

4. “Fonts” will erase font caches for specific applications. This is useful when Word or Photoshop gets hung up loading fonts and needs to be reset.

mac maintenance onyx cleaning fonts

5. “Logs” will clear out system and user logs of various events on your system. If your log files are getting massive, this is a quick way to erase them all.

mac maintenance onyx cleaning logs

6. “Misc.” includes a bunch of odd-man-out caches, like saved Calculator values, Recent Items, and the My Computers list in Screen Sharing.

mac maintenance onyx cleaning misc

7. “Erasing” allows you to select and securely erase a file or folder. The higher up the list you go, the more secure the erasing process is, but the longer it will take.

mac maintenance onyx cleaning erasing

8. Finally, “Trash” will empty your trash. You can select the default delete process, or tick “Secure Delete” to overwrite the trash data with three passes of garbage data. Secure Delete isn’t a great option for modern Macs running SSDs though, so it might better to avoid it.

mac maintenance onyx cleaning trash


mac maintenance onyx menu bar automation

With the “Automation” tab, you can automate many of the tasks from the “Maintenance” and “Cleaning” menus. Essentially, it allows you to run a subset of the most popular tasks with the click of a single button.

mac maintenance onyx automation

You’ll notice that some of these items are ticked off by default. This is to avoid clearing out important or large database accidentally. Before you click “Execute,” make sure you actually want to delete all the stuff above, since your system will need to rebuild it at some point.


mac maintenance onyx menu bar utilities

The “Utilities” tab includes a variety of useful programs that don’t fall under cleaning or maintenance tasks. This is also where Onyx stores its custom functions.

1. “Manuals” includes all the man pages for various Terminal commands. You can search using the search box on the bottom of the screen, and click “Create PDF” to build a PDF of the open man page.

mac maintenance onyx utilities manuals

2. “Finding” allows to you to search the locate database on macOS. It runs faster than find for large searches, and searches for every instance of a given path name. Click “Create” to build the database, and then use the search menu at the bottom to find files.

mac maintenance onyx utilities finding

3. “Process” does nothing by default. If you turn on Process Accounting by clicking the “Turn On” button, Onyx will start keeping a log file of every process on your Mac. As you might guess, this file can get very large very fast, but it’s valuable for troubleshooting specific program issues.

mac maintenance onyx utilities process

4. “Visibility” allows you to toggle the “hidden” attribute of hard drives, files, folders and applications. This is useful for tucking away private files, or hiding Windows partitions on dual-boot systems. Use the “Hide” button to select a file, folder, or disk for hiding, and the “Show” button to select a hidden file to reveal.

mac maintenance onyx utilities visibility

5. AppleDouble will delete AppleDouble files, which start with ._ and are created when applications need to write metadata to an unsupported disk format, like MS-DOS format. These files aren’t typically erased when the program is finished, so they can clutter up disks quickly.

mac maintenance onyx utilities appledouble

6. “Packages” will show you the content of a specific .pkg file. This is useful for inspecting less-than-trustworthy distributions.

mac maintenance onyx utilities packages

7. “Checksum” will run a variety of checksum routines on a given file. Great for verifying the validity of a downloaded program.

mac maintenance onyx utilities checksum

8. Finally, “Applications” is essentially a shortcut to /Applications/Utilities, with buttons to launch a few hard-to-find system programs.

mac maintenance onyx utilities applications


If your a Mac power user, Onyx is a great way to get a handle on your Mac maintenance. It makes a lot of hidden functions more easily accessible, and includes some useful new utilities, like checksumming, to make your life easier. It also makes it possible to quickly customize a wide variety of parameters on your Mac: check out the “Parameters” tab for more options there!

You might also like:

5 Ways To Clean and Maintain OS X Mavericks
How to Customize Notification Center in OS X Yosemite
Lesser-Known Mac Tips, Tricks, and Customizations


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Alexander Fox

One Comment

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  1. HI,
    Relatively new used from windows. Gave up on cocktail with this Mojave update and decided to look for something else. Came across Onyx. I downloaded the Onyx from the website and installed However, my bar only displays maintenance , utilities, files and parameters. I do not see options for cleaning and automation etc. My hope was to set it up to do routine maintenance once a week or so at 4am while I was sleeping but am not sure how to set that up with the options displayed in this version ov onyx which is 3.6.4 DO I need to download the other utilities (deeper and maintenance) to get those features? thanks

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