Safe App to Clean Mac System Files?

senior contributor neuroanatomist wrote a very nice discussion of how to fix this issue, including some suggested utilities that can help YOU identify what big things are clogging your storage. These utilities do NO removal, only identification.

How to free up ‘System Data’ and other st… - Apple Community

As others have emphasized, THERE IS NO AUTOMATIC WAY to reduce this use of Storage, and the Apps that claim to do so such CleanMyMac are absolute JUNK, can be damaging to your Mac, and should NEVER be installed on your Mac.

If you mean anything in the System folder, you can't remove, add of modify anything within. Period.

As far as hidden files and folders, being Unix underneath, there are thousands of them. Hidden for a reason, like the user going nuts and deleting things without knowing what they're for and making your Mac un-bootable.

before you can make progress on this issue, you need to know what are the top items consuming your storage:

I continue to recommend using one either:

• System Settings > General > Storage

• one of the third-party utilities mentioned in neuroanatomist article

Once you have discovered what and where the biggest files are, then (and only then) can you take steps to solve the problem. Any other way is just blindly stabbing at the problem, and unlikely to achieve any meaningful results.

May I suggest that you take a step back and explain your desire to do what you propose doing. You may be laboring under a misconception — the result of utter lies promulgated by companies that seek to profit by selling either worthless or destructive products.

Excerpted from Effective defenses against malware and other threats - Apple Community:

Never install any product that claims to "clean up", "speed up", "optimize", "boost" or "accelerate" your Mac; to "wash" it, "tune" it, or to make it "shiny". Those claims are absurd.

• Such products are very aggressively marketed. They are all scams.
• They generally operate on the flawed premise that a Mac accumulates "junk" that needs to be routinely "cleaned out" for optimum performance.
• Trial versions of those programs are successful because they provide the instant gratification of greater free disk space.
• That increased space is the result of irreversible destruction of files, programs, or operating system components normally protected from inadvertent alteration or deletion. The eventual result will be unreliable operation, poor performance and random crashes that may not become evident for months or even years after their use, when updates to programs or macOS are eventually released.
• ...

Rule 1 of Macs is don't install junk. If you want to remove items you don't need, refer to the Apple Support document I referenced earlier. Use the Finder to do that, and don't do anything without a backup.

⛔️ Don’t tamper with restricted files you know nothing about! ⚠️

MacOS is the most secure operating system on the market. Privacy is at the very core of all Apple products and services.

I would advise against installing anything that interferes with that.

Don’t be fooled by clever marketing advertisement tactics that rely on fear to sell you a solution to a problem that doesn’t exist.

All the best! 👋🏼😉

We may be able to extend our recommendations if you post a system config report. Fortunately there is a safe, secure way to do so.

To create a data-driven evaluation in this setting where we can neither see nor touch your computer, please post an EtreCheck report. We can quickly and within the limitations of these forums help you determine what issues are at play without our playing a protracted game of "20 Questions" with you that could go on for days. 

EtreCheck Pro is available here: https://etrecheck.com/index

The free version will do nicely for this purpose, although the app is worthy of our financial support.

We can see hard data about drive performance, software issues and interferences, and RAM usage. Etrecheck is the development of a long-serving and trusted ASC contributor. It is a reporting app, not a "fix-it” app, expressly for displaying information in Apple's forums to help us help you remotely. It will not reveal any personal or secure information.

Please see this excellent user tip on how to post long text reports like EtreCheck's into a forum response:

How to use the Add Text Feature When Post… - Apple Community

Please post the entire report. What seems insignificant to a new Etrecheck user can speak volumes to those of us who have reviewed thousands of those reports. 

premchavan wrote:

... trying to delete old backups, cache files, and other unnecessary system support files. Could someone please recommend a reliable, Apple-authorised application that can safely clean these unwanted files without any hassle?

"old backups"? What old backups? Apple's Time Machine cleans up after itself, and if you can delete any of the backup files, the rest of the backup won't work anymore! Individual third party programs, like Adobe Lightroom, create certain files to back up its catalogs, and many of those can be safely deleted simply through normal Finder operations, if they take up lots of space. I would leave cache files alone, except through an option that the software itself presents (e.g. delete cache files in Safari, Firefox, etc.)

If you make iPhone backups to your Mac, there is a Mobilesync directory in your user Library and you can delete any files in there, understanding of course that this eliminates the possibility of using them to restore an iPhone. And software that downloads big files for devices (such as Garmin software downloading big map or update files) often leaves those files in its Application Support folder. If you know what you are doing, you can delete those if no longer needed.

In general, I would stay away from any tools that claim to add value by "cleaning" your Mac.

Here you go: Optimize storage space on your Mac - Apple Support

There are no "Apple-authorised" applications for this.

There aren't even any Apple-recommended apps for this.

See the good guidance provided by our friend @John Galt.