Before
When you have a few tabs open things are not so bad. But if you have something like 30+ tabs open then Firefox is definitely going to have a much larger memory footprint. For the moment all six tabs are active in our example…
After
Once the extension is installed you can see quite a difference in the tab bar. Five of the six websites are literally on hold and display as about:blank.
In the screenshot above all six tabs were restored from a previous session, but to put new tabs on hold the preferences will have to be modified.
Notice that you can have active tabs placed on hold if you do not access them within a set time (“x” seconds, minutes, hours, or days). You may also add your favorite websites as exclusions.
Newly opened tabs can now be placed on hold until you are ready for them.
Need to place a currently accessed tab on hold? Use the tab context menu to unload the page.
Once you use the tab context menu to place a tab on hold your browser will shift over to the closest active tab.
You will notice the difference in memory usage when you put a lot of intensive pages on hold.
Conclusion
If you keep a high number of content heavy webpages open in Firefox then the BarTab extension will help reduce memory usage while browsing.
Links
Download the BarTab extension (Mozilla Add-ons)