Since Yesterday, Safari keeps hanging.

Go step by step and test.

 1. Restart your Router.

     Startup in Safe Mode. https://support.apple.com/en-us/HT201262

     Launch Safari and test.

     Restart normally by clicking the “Restart” button at the bottom.

2. https://support.apple.com/en-us/HT203353

3. Check for adware.

     Use  the latest release of Malwarebytes for Mac to remove malware/adware, if installed on your Mac.

     For instructions:  Install Malwarebytes for Mac          Uninstall Malwarebytes for Mac

     Click the “Scan Now” button. Once done, quit Malwarebytes for Mac.

     Restart the computer and relaunch Safari holding the shift key down.

4.  If this doesn’t help:

     Download EtreCheck: https://etrecheck.com/maspro.

     Click  “Click to download” button,    

     Open Downloads folder, click on it to open, and then select ”Open”.

     “Choose a problem” from the popup menu box, and then “Start EtreCheck” in the dialog.

     Click “Share Report” button in the toolbar, select “Copy report” .

     Paste the report when you reply.

If the above doesn't work, you can try the below.

Safari/Preferences/Advanced - enable the Develop menu, then go there and Empty Caches. Quit/reopen Safari and test. Then try Safari/History/Show History and delete all history items.  Quit/reopen Safari and test. You can also try try Safari/Clear History…. The down side is it clears all cookies. Doing this may cause some sites to no longer recognize your computer as one that has visited the web site. Go to Finder and select your user/home folder. With that Finder window as the front window, either select Finder/View/Show View options or go command - J.  When the View options opens, check ’Show Library Folder’. That should make your user library folder visible in your user/home folder.  Select Library/Caches/com.apple.Safari/Cache.db and move it to the trash.

Go to Safari Preferences/Extensions and turn all extensions off. Quit/reopen Safari and test. If okay, turn the extensions on one by one until you figure out what extension is causing the problem.

 Safari Corruption       See post by Linc Davis

If that doesn't work, try running this program in your normal user account , 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. On the screen with Options, please open Options and check the bottom 2 boxes before running. Click “Share Report” button in the toolbar, select “Copy Report” 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        Pastebin

Etrecheck – System Information

Lately Safari as a browser has many problems and you can also try Google Chrome, Opera and Firefox. Maybe that will work for you. In the past I've been using Safari to watch Netflix, but I keep getting the spinning ball over and over again. I gave up on Safari and now use the others that I listed above. On Safari watching my news video on local stations in San Francisco, Ca the video stops and voices can't be heard at all. Restart my computer and it happen again with Safari and now use Firefox and no problems at all for me. I have a MacPro desktop computer.

You are welcome.