Click on Safari and then on Preferences. In the Preferences window, click the Advanced tab and make sure the checkbox next to Show Develop menu in menu bar is selected. Select Develop in the menu bar at the top of the screen and select Empty Caches. Your cache and temporary files have been cleared.
To clear recents in Mac Finder:
Using Terminal to Completely Clear the Clipboard Launch Terminal, which is located in the "Utilities" folder inside the "Applications" folder. Type or paste "pbcopy < /dev/null" in the Terminal window and press "Enter." This clears the clipboard.
How to reduce RAM usage on a Mac
In the Mail app on your Mac, do one of the following:
Reduce the size of your iCloud Backup
Use Erase All Content and Settings in System Preferences From the Apple menu in the corner of your screen, choose System Preferences. From the System Preferences menu in the menu bar, choose Erase All Content and Settings.
Clear the Web Browser Cache - Safari
Clearing up individual app caches is often straightforward:
Compress a file or folder: Control-click it or tap it using two fingers, then choose Compress from the shortcut menu. If you compress a single item, the compressed file has the name of the original item with the . zip extension. If you compress multiple items at once, the compressed file is called Archive.
Tag an open file: Hold the pointer to the right of the document title, click the down arrow , click in the Tags field, then enter a new tag, or choose one from the list. Tag a new file when you save it: Click File > Save. In the Save dialog, click in the Tags field, then enter a new tag, or choose one from the list.
Move items into folders On your Mac, click the Finder icon in the Dock to open a Finder window. Do any of the following: Put an item in a folder: Drag it to the folder. Put several items in a folder: Select the items, then drag one of the items to the folder.
Just press Command-O in your app, navigate to the file, select it, and click Open or press Return. If you want to view a file when you're in an Open dialog, you can select and it press the space bar to view it in Quick Look.
Click the desktop, choose View > Sort By, then choose an option. If you want to control the placement of your files on the desktop, keep Sort By set to none. You can still arrange files neatly when desired—just click the desktop, choose View > Clean Up By, then choose how you'd like to arrange the files.
Delete an item from your Mac or iCloud Drive On your Mac, drag the item to the Trash in the Dock or select the item, then press Command-Delete. If an item is locked, click Continue to confirm you want to move the locked item to the Trash.