There is a new fork https://addons.mozilla.org/addon/discard/

Great ! The only problem I have is that the addon doesn't know hidden tabs so I regularly stumble upon one when I unload a tab.

Works, but I wish it also worked with multiple tab selection.

Work as it should

Works as it should in FF 62.
There's a slight issue tho: If you choose unload tab while the tab contents are still loading, the favicon on the tab stays the animated loading indicator until you load the tab again.

Thank you, Js, this is the only tab unloading extension that works with my Firefox, because it uses the native command browser.tabs.discard(tab.id) instead of the ported chrome.tabs.discard(tab.id) like all others.
So, to all those who have commented at other tab unloading/suspending/discarding extensions that those don’t work for them: use this one.
And to all the developers who happen to visit here: Mozilla’s online documentation for its Web Extension API specifically states the browser.xxx architecture. User it, don’t be lazy and expect Chrome porting to always work. Not all of us have Chrome Store Foxified.
Spread the word if you know any developers personally. This is important. Thank you.

good intention mod, but it didnt work...QQ

Works as it should on my FF61. Unloads tab and frees memory.

Simple and functional

Indeed, it doesn't work. I hope it gets fixed soon.

I don't even get an "Unload tab" menu entry in the context menu (neither by right clicking on the page itself, nor by right-clicking on the tab in the tab bar). Please update it to work with FF57, or edit the description to make the requirements clear.

It does not work. It worked once one day, but no more.

Can confirm that the Unload Tab menu option does nothing.

I wish it would work, but it doesn't. Clicking unload on a tad does nothing. Please fix as this extension is very useful (and I need something like this btw...)

Finaly updated to new api, I've been expected this for so long. Thanks dev.

Does absolutely nothing

This is the function I need. Right click tab and choose "unload tab" - screen changes to white background that says its unloaded and "click to reload". But as others found I saw very little RAM released from multiple tab unloads.

Feature requests: if Firefox can monitor system RAM and optimize its RAM use to suit the system. Allow users to set max RAM use, and then have Firefox unload tabs as needed. Which tabs? Maybe options such as the oldest loaded or something logical. Allow user to "white list" some tabs so they are not unloaded.

Unfortunately firefox revolutions ruins my experiences and any fun moments I ever remember like unloading tabs ;)