Throttle Bandwidth on MAC OS X

To limit the connection speed on your Mac to a 56k modem for testing your website loading speed, pop this into terminal:

sudo ipfw pipe 1 config bw 56kbit/s
sudo ipfw add pipe 1 dst-port http

You can change 56kbit/s to any speed you want to test with.

To clear it either reboot or use:

sudo ipfw flush

via ( – Traffic Shaping in Mac OS X)