Safari keeps crashing on my MacBook with macOS Sonoma.

Start Safari version 17.4 (19618.1.15.11.12 ) in a Safe Launch Mode

Hold the SHIFT key and launch Safari

Still issues >>

Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal.

Safe Mode will also eliminate Third Party Software, extensions and drivers from loading. It will only load the Minimum amount of Core Apple Processes to allow the the computer to function at a reduced Level of Performance 

Does the issue present in this mode ?

Sometimes a Safe Boot followed by a Normal Boot will just put things right.

Still issue >>>

If not - there could be something in the main User Account playing up. To further isolate this - Set up users, guests, and groups on Mac. Then log out of the Main User account and log into the dummy account and test again if the issue persists.

If the issue is present in the dummy account - then, this appears to be a System Wide issue on the computer.

Still issues >>>>

Download the Application Etrecheck  ( External Link ) directly from the Developer.

The Application is Not a " Silver Bullet "  and is  only a tool to examine the Hardware / Software used on this computer 

This is a Diagnostic Tool that makes no changes to the computer Hardware / Software used on this computer 

The application is free or paid from added features. 

The Report will Not Reveal Any Personal Information. 

Post back the Full Report - copy and paste - >>>> using the Additional Text Icon ( 3rd Icon to last ) <<<<

Lastly - should you decide to use and post the Report now or at a later time, we are willing to have a very close look and offer some insights 

Good idea but looking at the Outdated Etrecheck application report

Think one will find some interesting Third Party Software used and installed on this computer

Have a look 😎

Unsigned files - There are unsigned software files installed that could be adware and should be reviewed.

Network:

  Interface en8: Ethernet Adapter (en8)

    Proxy Auto Config: 

  Interface en10: Ethernet Adapter (en10)

    Proxy Auto Config: 

  Interface en11: Ethernet Adapter (en11)

    Proxy Auto Config: 

  Interface bridge0: Thunderbolt Bridge

    Proxy Auto Config: 

  Interface en0: Wi-Fi

    802.11 a/b/g/n/ac/ax

    Proxy Auto Config: 

Configuration Files:

  File /etc/sysctl.conf exists but not expected

All hallmarks of Adware infestation

Antivirus software: Apple and AdGuard

Third Party Security Software 

Any of the below should be removed as per Developers Instructions 

Ad Guard,

1. Update Software

- Ensure macOS and Safari are up to date. Go to Apple Menu > System Settings > General > Software Update and install any available updates.

2. Clear Cache and Website Data

- Open Safari, go to Safari Menu > Settings > Privacy > Manage Website Data. Click Remove All to clear cache and website data.

3. Disable Extensions

- Sometimes extensions cause crashes. Go to Safari Menu > Settings > Extensions and disable all extensions. Enable them one by one to identify the problematic one.

4. Check for Conflicting Software

- Some third-party software can cause Safari to crash. Boot your Mac in Safe Mode by holding the Shift key during startup and see if Safari crashes. If it doesn’t, the issue might be due to third-party software.

5. Reset Safari

- Reset Safari to default settings. Go to Safari Menu > Settings > Advanced, enable the “Show Develop menu in menu bar,” then go to Develop Menu > Empty Caches and Develop Menu > Disable Extensions.

6. Check for Malware

- Run a malware scan using a trusted tool like Malwarebytes to ensure your Mac is not infected.

7. Reinstall Safari

- If the issue persists, you might need to reinstall Safari. This requires reinstalling macOS, which will also reinstall Safari. Make sure to back up your data before doing this.

8. Contact Apple Support

- If none of the above steps work, contact Apple Support for further assistance.

Since Safari opens in a guest profile it may be something carried over in the signed in profile.

Did you try clearing the Safari Cache and turning off extensions? Due to the nature of third party extensions it isn't unusual for them to break and cause glitches. I prefer turning my extensions on and off as needed.

1. Choose Safari > Settings (or Preferences), then click Extensions.
2. To turn off an extension, deselect its checkbox.

How many tab groups and profiles do you have in the safari browser?

It sounds to me that something is running in the background and limiting the processing memory.

Kindly try the following steps:

1. Open Finder
2. Select Applications in the left sidebar
3. Open the Utilities folder
4. Double-click Activity Monitor
5. Click the Memory tab

Current version Etrecheck Application is EtreCheckPro version: 6.8.4 (68040)

Your version is EtreCheck version: 5.7.2 (5247)

Suggest using the current version as it may give far better insights and details

Then post back if you would and please

Kindly understand tabs in a tab group on a Mac remain active after opening them, and you can quickly switch between them. However, tabs from a previous group remain in memory until you quit.

If an open tab has a lot of active content such as animations, active games, short videos, anigifs, JavaScript applications, weather maps, embedded objects and etc... it uses the devices ram.

Plus tab groups were meant to allow for organizing tabs together, which can help you stay on top of a project. Tab groups were not created to take the place of bookmarks. Note tab groups are a way to organize tabs, while bookmarks are a way to save pages

The next time you experience the issue do yourself a favor and check your Macs activity monitor to see if the memory usage spikes and what is causing the spike. If memory use is limited it may cause the type of glitch you are experiencing.

I found this resource which shares 11 possible fixes for when the Safari browser crashes: https://www.macobserver.com/tips/how-to/safari-crashing-mac/

Have you tried eliminating the last website or two that was added to the group before it started crashing? I understand a website with poor coding may crash a tab group.

Current Version Etrecheck has the ability to remove malware and other Bad Actor software