OneTab extension for Chrome web browser is very useful if you want to lower down the memory consumption of the web browser and reduce the tabs clutter. According to the developer, it can lower the memory usage up to 95% by removing all the open tabs and adding them to a single tab in form of a list in OneTab.
In order to use the OneTab extension to close all the tabs and put them on the OneTab list all you have to do is right-click anywhere in any tab, select OneTab and then Send all tabs to OneTab. There are many other choices available from the context menu such as sending only the current tab to OneTab, sending all other tabs (except the current tab) to OneTab, send all the tabs right to the current tab, send all the tabs left to the current tab and more.
OneTab extension can be used whenever you have opened dozens of tabs in the Chrome web browser. It will instantly close all the open tabs and open just one tab that shows you a list of tabs that have just been closed. In this tab, you can see the number of tabs in the list, the URLs of each of closed tabs, you can manually export/import the URLs, you can delete them all or restore them all back.
In the options for the OneTab extension, you can choose whether the list of closed tabs is opened in a new window, whether pinned tabs are also used with OneTab, whether OneTab is to be shown in a tab as soon as you launch the Chrome web browser, whether duplicate tabs are allowed, whether OneTab list is cleared upon restoring the tabs and more.
You can get the OneTab extension for Chrome web browser from https://chrome.google.com/webstore/detail/onetab/chphlpgkkbolifaimnlloiipkdnihall/.