Download xpi and open the file with Firefox. After restarting your browser, configure through the menu item in Tools->DevCache or the Preferences button in manage addons dialog. Simply add the regex patterns for domains you want to disable disk and memory caching for. For example dev.example.com or http://www.example.com/dev/ sha256sum for releases: e80662691730a64af18bfdd35d8c38e8dabf02c32ae8be5538c9cf9bf61e8a09 xpi/devcache-1.0.2.xpi fa78b242305c1d0842bcf362d94659fc747749360e8e676d703976ce8215f2e5 xpi/devcache-1.0.3.xpi Enjoy!