Best Mac Cleaning Tools: A Roundup of the Most Practical Apps in 2025

Why Does Your Mac Get Slower Over Time? System Junk Is the Culprit

After a year or two of using your Mac, have you noticed these issues: slower boot times, apps taking forever to launch, or storage space mysteriously filling up? Don't rush to buy a new computer — the problem is likely system junk.

With daily use, your Mac continuously accumulates cache files, uninstall leftovers, and redundant data. The Verge's tech recommendation column Installer dedicated its 128th issue to recommending noteworthy Mac cleaning apps that help users efficiently organize and optimize their systems. Based on that recommendation, this article provides a comprehensive guide to choosing the right Mac cleaning tool.

Where Does Mac System Junk Come From? These "Invisible Killers" You Might Not Have Noticed

Many Mac users don't realize that even with good usage habits, various "invisible junk" quietly accumulates in the system:

• Application cache files: Browsers, development tools, and design software generate massive amounts of cached data every day. Cache is essentially a classic computer strategy of trading space for time — applications temporarily store frequently accessed data on local disk to avoid re-reading it from the network or deep disk storage every time. For example, Safari and Chrome cache HTML, CSS, JavaScript, and image resources from web pages, significantly speeding up load times on subsequent visits to the same site; development tools like Xcode cache compilation intermediates (Derived Data), with a single project's cache potentially ballooning to several GB. These cache files are typically stored in the ~/Library/Caches/ directory, and macOS doesn't proactively set expiration cleanup mechanisms for them, so cache volume continues to grow over time.

• Uninstall leftover files: Dragging an app to the Trash ≠ complete deletion — preference files and support files are often scattered across various system directories. This relates to macOS's application distribution model — most Mac apps exist as .app Bundles, which are directory structures containing executables, resources, and frameworks. When users drag an .app to the Trash, they're only deleting the Bundle itself, but during runtime, applications write data to multiple system directories: plist preference files in ~/Library/Preferences/, user data in ~/Library/Application Support/, sandbox data in ~/Library/Containers/ and ~/Library/Group Containers/ (for App Store apps), and background service configurations in LaunchAgents. These scattered files aren't automatically removed when the app bundle is deleted, forming substantial "digital debris" over time.

• System logs and temporary files: macOS itself continuously generates logs and temporary data

• Duplicate files: Multiple copies of photos and documents silently occupy precious SSD space

These files accumulate over time and can consume tens of GB or more of storage space. The impact is especially noticeable for users with 256GB or 512GB SSDs. It's worth noting that modern Macs exclusively use NVMe protocol solid-state drives, whose read/write speeds far exceed traditional mechanical hard drives. However, SSDs have an often-overlooked characteristic: performance drops significantly when storage approaches capacity. This relates to SSD Garbage Collection and TRIM mechanisms — SSDs must erase entire data blocks before writing new data, and when available space is insufficient, the controller must frequently perform data migration and block erasure operations, causing Write Amplification to intensify, with write speeds potentially dropping to 50% or even lower than normal levels. The industry generally recommends keeping at least 10%-20% of SSD space free to ensure the controller has sufficient operational headroom to maintain optimal performance. So your Mac slowing down isn't just a "psychological feeling" — insufficient storage space genuinely drags down your computer at the hardware level.

Why Manual Cleaning Isn't Reliable

macOS includes basic storage management functionality (accessible via "About This Mac" → "Storage"), but it's quite limited. Manually cleaning leftover files deep within the Library folder is not only time-consuming and labor-intensive but also risks accidentally deleting critical system files.

It's worth explaining macOS's Library folder structure here. The system actually contains three different levels of Library directories: /System/Library/ (system-level, protected by SIP — System Integrity Protection — and unmodifiable by users), /Library/ (resources shared by all users on the machine), and ~/Library/ (exclusive to the current user, and the primary gathering place for junk files). Starting with macOS 10.7 Lion, Apple set ~/Library/ as a hidden directory by default — users need to hold the Option key and click the "Go" menu in Finder to access it. This design was intended to prevent ordinary users from making mistakes, but it also objectively makes junk files easier to overlook. Subdirectories like Caches, Logs, Application Support, and Saved Application State under this directory are precisely the areas that cleaning tools focus on scanning.

This is why a professional Mac cleaning tool is practically essential — they can safely delve into these hidden directories, precisely identify deletable files, while avoiding critical system components.

How to Choose a Reliable Mac Cleaning Tool? Look for These 5 Criteria

Based on The Verge Installer column's recommendation logic and actual user feedback, an excellent Mac cleaning app should meet the following conditions:

1. Proven safety: Accurately identifies files safe to delete, never accidentally removing critical system components
2. Comprehensive cleaning scope: Covers caches, logs, language packs, mail attachments, large file scanning, and other dimensions
3. Low learning curve: Intuitive and clear interface that's easy to operate without technical background
4. Transparent operation: Clearly displays what will be deleted, leaving the final decision to the user
5. Lightweight footprint: The cleaning tool itself shouldn't become a new burden on the system

2025 Mainstream Mac Cleaning Tools: Side-by-Side Comparison

The Mac platform currently has three well-regarded cleaning tools, each with different strengths:

CleanMyMac X: The Most Comprehensive All-in-One Solution

CleanMyMac X is the most feature-rich option among Mac cleaning tools, integrating system junk cleaning, malware scanning, performance optimization, and app uninstall management modules. It features a beautifully designed interface with a foolproof workflow.

CleanMyMac X is developed by Ukrainian software company MacPaw. One of its core technologies is a built-in Safety Database that maintains a detailed whitelist of critical system files, ensuring the cleaning engine automatically skips components essential for macOS to function normally. The application has also received Apple's Notarization, meaning it has passed Apple's automated security checks and contains no known malware. Its malware scanning module is based on MacPaw's proprietary threat signature database, capable of detecting common Mac platform adware, ransomware, and Potentially Unwanted Programs (PUPs).

However, it uses a paid subscription model (approximately $39.95 per year for a single Mac, with a one-time purchase option also available), making it suitable for users willing to pay for comprehensive functionality.

AppCleaner: A Free, Lightweight Uninstall Powerhouse

AppCleaner focuses on doing one thing — helping you completely uninstall applications along with all their associated files. It's completely free with a tiny footprint; just drag an app icon into it and it scans for all related files. If your core need is cleanly uninstalling software, AppCleaner is the best choice. It automatically searches the previously mentioned ~/Library/Preferences/, ~/Library/Application Support/, and other directories for all files associated with the target application, listing them all at once and allowing users to check and delete them, fundamentally solving the leftover problem of macOS's native uninstall mechanism.

OnyX: The Swiss Army Knife for Advanced Users

OnyX leans toward system-level maintenance and advanced settings adjustment, capable of performing disk verification, rebuilding caches, cleaning system files, and other operations. It's free and open-source, but has a relatively plain interface, making it more suitable for users with some macOS technical background.

OnyX is developed and maintained by French independent developer Joël Barrière (screen name Titanium), continuously updated since the Mac OS X 10.2 Jaguar era, making it one of the longest-running free maintenance tools in the macOS ecosystem. One of its core functions is triggering macOS's built-in maintenance scripts (daily, weekly, monthly maintenance scripts) that aren't exposed to ordinary users — these scripts handle tasks like cleaning system logs and rebuilding locate and whatis databases. OnyX can also rebuild various system caches, including kernel extension cache (kextcache), font cache, Spotlight index, and DYLD shared cache. Notably, OnyX strictly follows a macOS version-matching principle — each major macOS version has its own dedicated OnyX version that cannot be mixed, ensuring complete compatibility between the tool and system APIs.

Quick Comparison of the Three Tools

Tool	Price	Core Features	Best For
CleanMyMac X	Paid subscription	Comprehensive cleaning + optimization + security	Users seeking an all-in-one experience
AppCleaner	Free	Complete app uninstallation	Users with targeted uninstall needs
OnyX	Free	System maintenance + advanced settings	Advanced users with technical background

Practical Mac Cleaning Tips: Good Habits Beyond Tools

Tools alone aren't enough — developing these habits will keep your Mac running smoothly long-term:

• Run a scan monthly: Spend a few minutes running a cleaning tool to prevent junk file buildup
• Use professional tools to uninstall apps: Stop dragging apps directly to the Trash — use tools like AppCleaner to ensure clean removal
• Regularly check for large files: Use your cleaning tool's large file scanning feature to find forgotten bulky files
• Make good use of iCloud storage optimization: Transfer infrequently used files to the cloud to free up local space. macOS's built-in "Optimize Mac Storage" feature is an intelligent iCloud Drive capability — once enabled, the system monitors local disk available space and, when space runs low, automatically keeps recently unaccessed files only in iCloud, leaving just a placeholder that takes up minimal space locally. Users can still see these files in Finder, and the system downloads them from iCloud in real-time when clicked. This mechanism is implemented based on features of Apple's APFS (Apple File System), which natively supports sparse files and cloning among other advanced features, making the local presentation of cloud files more seamless. Note that iCloud free space is only 5GB, and actual use typically requires subscribing to a paid plan (50GB for ¥6/month, 200GB for ¥21/month, 2TB for ¥68/month).

Final Thoughts

Keeping your Mac clean and efficient doesn't require complicated procedures. Choose a cleaning tool that suits your needs, pair it with good usage habits, and your computer can stay in peak condition. In an era where SSD storage space is precious, a good Mac cleaning app isn't a luxury — it's a genuine necessity.

As a side note, The Verge Installer Issue #128 also discussed the industry phenomenon of screenwriters transitioning to AI trainers, reflecting AI technology's profound impact on creative industries — also worth paying attention to.