You could try disabling your less critical extensions and see whether that resolves the issue. You also can try updating extensions in case there is a compatibility issue with your current version of Firefox. Open the Add-ons page using either: * Ctrl+Shift+a * "3-bar" menu button (or Tools menu) > Add-ons In the left column, click Extensions. Above the list, click the "gear" button and Check for Updates. Then review the list and, if you can live without an extension for 24 hours, disable it. Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step. Does that help improve performance? ---- When you tested, did you use the feature of restarting Firefox in Safe Mode (there is a little dialog with a choice between Safe Mode and Refresh)? Safe Mode also disables Firefox from using "hardware acceleration" which sometimes bypasses compatibility issues with your graphics card/graphics chipset. That usually is more of a crashing problem than a slowness problem, but if you want to try disabling Firefox from using hardware acceleration in normal mode, you can do that here: "3-bar" menu button (or Tools menu) > Options > Advanced On the "General" mini-tab, uncheck the box for "Use hardware acceleration when available" This takes effect the next time you exit Firefox and start it up again.