How to make a slow browser go fast? I've had my MacBook Air for about six months. Now all the browsers are extremely sluggish — sometimes taking minutes to load a web page that would have used to take under one second to load back when everything was new.

Questions


What's causing the sluggish browser response? (Most likely.)
What is a stepwise procedure to troubleshoot and/or fix it?


Configuration Details


O/S: OS X Yosemite 10.10.5
Memory: 4 GB @ 1600MHz DDR
Browsers: Safari, Chrome
Changing my DNS settings to Google's DNS servers 8.8.8.8 and 8.8.4.4 seems to help a little but might not be the comprehensive solution I was looking for.

Procedure

Bottom toolbar > System Preferences > Network > Advanced... > DNS > + > 8.8.8.8 > + > 8.8.4.4

Or, via command line:

networksetup -setdnsservers Wi-Fi 8.8.8.8 8.8.4.4


The procedure is detailed here.