Q: Safari has slowed down to a crawl since installing Yosemite OS.

Hi MinaF,

Welcome to the Support Communities!  I've included some resources below to address the issue you are having with Safari.  I'm curious to know if you've tried a different browser such as Firefox or Chrome to see if you get the same results.

Here are some things you can try with Safari:

Solutions for connecting to the Internet, setting up a small network, and troubleshooting - Apple Support

DNS issues - "Server Could Not Be Found", webpages load slowly

DNS-related alert messages

It's possible to successfully connect to the Internet but not be able to load webpages or do other things that use the Internet. You may see messages such as:

• "The server could not be found."
• "The specified server could not be found."
• "A connection failure has occurred."
• "Connection attempt failed."
• "Name servers not responding."

Delay before connection

In some cases, webpages might load, but you have to wait quite a bit before they do. This could be caused by DNS issues.
The domain name system (DNS) server, which is provided by your Internet service provider or network administrator, translates names like "www.apple.com" to their numerical IP addresses. For more information, see these articles:

• Mac OS: Long delay before webpages load, then load suddenly at normal speed
• Troubleshooting "A connection failure has occurred", "The specified server could not be found" or similar messages

Troubleshooting web browser issues

 

If your web browser can connect to the Internet but has other issues, such as quitting unexpectedly or becoming unresponsive ("freezing") there are other steps you can try.

Unsupported third-party add-ons may cause Safari to unexpectedly quit or have performance issues - Apple Support

Hopefully, one of these troubleshooting steps will resolve your issue.

Cheers,

Judy