Firefox Throttle is a extension for Firefox browser, that allows you to cap download/upload rates and monitor current bandwidth utilization. Its features include: Throttle localhost connections; Limit download and upload rates for all open Firefox windows/tabs and downloads; Bursting mode (allow short rate “bursting” after inactivity); Preset and custom limits; Configurable lists for IP addresses and domains that should not be throttled; Automatically excluded LAN IPs; Traffic stats (for current session and historic since last reset); Status panel with current bandwidth utilization indicators (or traffic counters); Quick throttling on/off toggle on status panel.

Download: Firefox Throttle