safari reducing available memory

Download and run Etrecheck. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support  to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

Copy the report

and use the Add Text button to include the report in your reply. How to use the Add Text Feature When Posting Large Amounts of Text, i.e. an Etrecheck Report

IMPORTANT:

Before running Etrecheck assign Full Disk Access to Etrecheck in the Etrecheck's Privacy preference pane so that it can get additional information from the Console and log files for the report:

Also click and read the About info to further permit full disk access.

Then we can examine the report and see if we can determine what might be causing the problem.

Booting into Safe Mode is always a good tool for fixing problems. Starting your Mac in safe mode does the following:

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

Glad you're back up and running smoothly.

There is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus or security apps on your Mac.  This user tip describes what you need to know and do to protect your Mac: Effective defenses against malware and other threats - Apple Community.   Trusteer Rapport falls into that category. Unless you're forced to use lit by a bank or employer uninstall it according to the developer instructions. As you've found out it does nothing but hinder performance.

What do you mean by getting a f.txt automatically?

Check the installed Safari extensions and disable them to see if there is a change.

Also check if some page you visit is having an impact on memory used.

And to check for other possible causes Please run Etrecheck and post its full report here.

Use the “additional text” button and paste the report into the text box.

You have shot yourself in both proverbial feet ☹️ by installing this creepware called cleanmymac. This is to be considered malware.

Furthermore you also have Trusteer and MalwareBytes. The latter is a decent program but it only should be run manually when there is a reason to.

For safe and normal operation you should have ZERO third party antivirus. You have THREE.

This can only lead to conflicts, degrading performance and decreased security.

Uninstall cmm and trusteer, and only run MalwareBytes manually.

Even then it is very likely that your system has already been damaged by cmm so you probably should do a clean install.

Hi, my iMac with 10.15.7 was being killed by Safari - it ended with Safari taking 75GB of memory (ie quite a bit of the hard disc!). Disabling Rapport did the trick. Also Safari stores lots of caches in memory which I delete via the developers menu when needed or when changing what I'm doing. Cheers Rob

How long has it been since you've rebooted?

Have you run any "cleaning", "optimizing", "speed-up" or anti-virus apps on your Mac?