I don't know of any Firefox setting that would do that, but perhaps
more important is *why* you would want to do that, and *what* you
expect to happen when you've reached the limit? Do nothing, issue
a warning, continue in a new window.
What I would suggest is installing "Tab Count" or "Tabs Counter" so that
you can see a tab count on a toolbar.
I would not be surprised if a single article had me open 20 tabs to
be read after reading the main article. I often open a bookmark folder
of blogs with about 20 bookmarks in such a folder. I have several sets
of those for reading at different times.
If you are having a problem with lots of tabs open, check
and the types of webpages you are opening (see next paragraph)
BTW, having lots of tabs open should not affect use of Firefox much
unless you have lots of such things as feeds, or web pages that refresh
themselves, such as news pages, or weather pages, as there
is only one Firefox open. I would not expect the same from Google
Chrome browser which has another instance open for each tab if I
understand correctly and there would be both advantages and
David McRitchie, extensions I use are briefly documented on my site
Firefox Custom: http://www.mvps.org/dmcritchie/firefox/firefox.htm
I find a crucial and important feature.
Being too sporadic in one's thinking might diverge one's concentrated
effort. On top of which older tabs don't get an alert for attention,
and thing get slow.
I think ti'll be great to have a max tab limit, with an alert, and a
way for old tabs to pop up a reminder or self terminated if unattended
after a second reminder.
A feature request or a firefox addon?
I believe such a thing should be a core feature.
Though you are not the original poster, it seems you both may
be experiencing problems due to certain sites.
I doubt that you will see a slowdown simply with more tabs,
certainly not with 50 or under (once loaded) if you have a computer purchased
in last three years. What will slow you down is if you load pages
that automatically refresh (such as some ads or newsfeeds) or are
currently running a flash file .
Extension TabMix Plus allows you to set the number of rows of tabs and
by also setting the size of the tabs the quantity is also limited.
However, what I've discovered is that apparently it merely hides tabs
that exceed the specified number of rows -- learned that by opening 4
rows of tabs and then deleting one at a time at the end returns those
that were at the start of the 1st row. So presumably these tabs
remain open to be updated.
However, I also use Add Block Plus and Element Hiding Helper which
prevents most ads from being seen and apparently stops their updating,
Adblock Plus: Element Hiding Helper :: Add-ons for Firefox
would that be the same as the Collapse option in AdBlock Plus itself.
Ablock had an option to either completely remove ads or to just hide them.