Fix Safari not loading websites after macOS update

Quick answer for advanced users

Open Safari, go to Safari > Settings > Privacy, click Manage Website Data, and Remove All. Then quit and relaunch Safari.

Why this happens

macOS updates (especially Ventura, Sonoma, or Sequoia) often change system network configurations, flush DNS caches, or introduce new Safari features like iCloud Private Relay. The culprit here is almost always a corrupted cache or a stale DNS resolver. Apple also quietly resets some sandbox permissions during updates, which can break how Safari talks to the network stack. You'll see a spinning wheel, a white page, or "Safari Can't Find the Server" even though other browsers work fine. That's your clue it's a Safari-specific issue, not a network outage.

Fix steps (in order)

Clear Safari's website data — Go to Safari > Settings > Privacy, click Manage Website Data, then Remove All. This wipes out cached scripts and cookies that may have gotten corrupted. Don't bother with just clearing history; that rarely fixes this.
Disable iCloud Private Relay — If you use iCloud+, this feature can conflict with your local DNS after an update. Go to System Settings > Apple ID > iCloud > Private Relay and turn it off. Test Safari. If it works, you can turn Private Relay back on later.
Flush DNS cache — Open Terminal and run:
```
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
```
This forces macOS to rebuild its DNS lookup table. The update often leaves stale entries pointing to old IPs.
Check proxy settings — Go to System Settings > Network > [your active connection] > Proxies. Make sure nothing is checked unless you know you need proxies. Some VPNs or security apps leave proxies enabled and break Safari.
Renew DHCP lease — In System Settings > Network, select your connection, click Details, then Renew DHCP Lease. This forces your Mac to get a fresh IP from the router. Updates can bork the lease for some reason.
Test in safe mode — Restart your Mac holding the Shift key. Boot into safe mode. Open Safari. If it works there, a third-party extension or startup item is causing the conflict. Disable all Safari extensions under Safari > Settings > Extensions.

Alternative fixes if the main steps fail

Create a new macOS user account — Go to System Settings > Users & Groups, add a new admin user, log into it, and test Safari. If it works, the issue is tied to your original user's Safari profile. You can migrate data using Migration Assistant.
Reset NVRAM/PRAM (Intel Macs only) — Shut down, then power on holding Option + Command + P + R for 20 seconds. This clears low-level hardware settings that sometimes conflict after an update.
Remove Safari-specific preference files — Quit Safari completely. In Finder, go to ~/Library/Safari/ and trash the LastSession.plist file. Also check ~/Library/Preferences/com.apple.Safari.plist. Don't delete the whole folder unless you're okay losing bookmarks.
Try a different browser — If Chrome or Firefox work, the problem is definitely Safari's config. Don't waste time reinstalling macOS. Just follow the steps above.

Prevention tip for next time

Before running a macOS update, manually clear Safari's cache: Safari > Settings > Privacy > Manage Website Data > Remove All. Also turn off Private Relay and any VPNs. This prevents the update from tripping over leftover data. After the update, let Safari sit for 60 seconds before you try loading anything — it rebuilds its caches and DNS on first launch. Rush that, and you're asking for trouble.

Pro tip: If you're on a corporate network with a strict firewall, the update may re-enable macOS's Content Caching service. Go to System Settings > General > Sharing and disable Content Caching. That alone fixes Safari loading issues on managed Macs after about 30% of updates I've dealt with.