- Open a new tab by typing Ctrl-t (That’s the Ctrl key on your keyboard and the letter t key at the same time)
- Enter about:config in the address bar of Firefox
- Enter ip into the Filter: text box
- Look for the network.dns.disableIPv6 entry in the table below the Filter: text box
- Double click the network.dns.disableIPv6 entry
- Restart Firefox
Firefox grinds to a halt while trying to find ipv6 internet addresses that are unavailable on most networks.
IPv6 is a new version of the IP protocol, and it isn’t supported on most netbook device. Therefore what was happening was that Firefox would try to use IPv6, wait until the request failed, and then try IPv4, that's painfully slow on your netbook.
After disable 'IPv6' feature, your Firefox will run faster about a hundred times more responsive.
(trick by techexplorer - written by Kerja Keras Adalah Energi Kita)