safari freezes.

Are you running any anti - virus programs?

Try setting up another admin user account in System Preferences/Users & Groups to see if the same problem continues. Please post back on whether or not this worked. Also try the Safe Mode. Please post back on whether or not this worked.

Isolating an issue by using another user account 

Safe Mode - About

If it works in the Safe Mode, try running this program when booted normally and then copy and paste the output in a reply. The program was created by Etresoft, a frequent contributor.  Please use copy and paste as screen shots can be hard to read. Click “Share Report” button in the toolbar, select “Copy to Clipboard” and then paste into a reply. This will show what is running on your computer. No personal information is shown. If the log won’t post, try posting it in Pastebin and provide a link in a reply. After pasting the report in a PasteBin page, go to the top of the page, and copy the address in the URL bar. Paste that in a new reply.        Pastebin

Etrecheck – System Information

Web site version if required.  https://etrecheck.com

You might want to consider starting a new discussion. Since this one is marked solved, less people are likely to look at it. A new post would be much more visible. You can link to this one. I suggest posting in the Catalina community.

macOS Catalina - Apple Community

Did you try what I suggested above - trying in another admin account and the Safe Mode?

You are welcome. I would uninstall Avast. It tends to interfere with the computer's operation while providing minimal to no benefit unless you work with Windows files. Most long time posters recommend not using antivirus software or cleaning software such as CleanMyMac.

Avast

Avast Un-install

Try turning off/disabling your VPN and test Safari.

You also might try quitting Microsoft Outlook because it is using a lot of memory.

I have same crashing issue but I'm not using safari. My MacBook Air freezes in any application. I have reinstalled MacOS Catalina but still facing same issue. Please help me.