Firefox uses too much memory or CPU

A few days ago Firefox started becoming unusable for me.

I usually have more than 10 windows and probably 40 tabs open at any time.

It was so slow I switched for a few days to Edge, which was much more responsive.

But I couldn't give up. I've been with Netscape Navigator, Mozilla Firebird and Firefox all my browsing life.

I fould this page from Mozilla really helpful.

In particular the option to "Minimize memory usage" in the about:memory page.

A combination of actions can really have an impact on the usability.

Disable Firefox Translation Pop-up

Open a tab and go to:

about:config

 

Search for the entry:

browser.translations.automaticallyPopup

 

Double click in the row to switch from true to false.

 

Done!

Thanks to Mozilla Support.

Reopen Last Closed Window in Firefox

If you accidentally or voluntarily closed a window and now you want it back, once there was the history menu item...
With the latest versions, you can use: cltr-shift-n. This will reopen the last closed window.
Tested with Firefox 59.

Thanks to NB_FF.

Configure Sun's Java Plugin for Firefox

1. Install the JRE or JDK as RPM or in your favorite location;
2. Open a shell and go to: ~/.mozilla
3. 64-bit platform: create the link: ln -s /opt/java/jdk1.7/jre/lib/amd64/libnpjp2.so . (the dot stands for the current directory)
4. 32-bit platform: search for the directory: i386.

Reference:
http://www.java.com/en/download/help/index_installing.xml

Fedora 10: Firefox Starts up in Offline Mode

The problem: upon strting Firefox it goes in offline mode even if the network is enabled and working. It's really unconvenient to un-check Work offline from the File menu every time especially if you start up many windows and tabs.
The quick solution is to stop and disable the Network manager application from the System --> Administration --> Services window.
Unless you need it... in that case I can't help you right now...

Java and Firefox 3 Beta 5 on Linux

This post is about configuring Java with Firefox 3 beta 5 on Linux i386. It might work for similar versions of Java and Firefox though.
The JRE coming with JSE v1.6.0_03 is currently not working. BUT the one coming with JSE v1.5.0_08 does work!
You just need to follow the usual instructions (which can be found here) and create a symbolic link the the Java plugin library:

> cd ${FIREFOX_HOME}/plugins
> ln -s ${JAVA_HOME}jre/plugin/i386/ns7/libjavaplugin_oji.so libjavaplugin_oji.so

Restart Firefox and check at this URL: about:plugins if it's loaded and here if it works.

Note: Actually "works" is perhaps a little bit of an overstatement. I found out an applet which is supposed to update itself with streaming data and is not doing it. So maybe it's a matter of waiting on Firefox's final version...
On the other side Firefox 3 is much much faster and less memory consuming than Firefox 2.