Clear the cache in your browser.

Internet Service - to check your speed, go to a site such as www.speakeasy.net and run the speed test.  3 mbps or higher should be adequate.
Wireless Router - the number of computers accessing internet can affect performance; and too much distance between the router and computers can hinder performance.
Web Browser - Chrome and Firefox are 2 of the faster browsers.
Go to a site such as YouTube and check your performance there.  If all is well, it could be that we are experiencing a server issue.
Computer age - as computers get older, they slow down.  You might be due an upgrade.